diff --git a/ui/src/common/track_adapter.ts b/ui/src/common/track_adapter.ts
index 9afa02b..35fe5db 100644
--- a/ui/src/common/track_adapter.ts
+++ b/ui/src/common/track_adapter.ts
@@ -17,6 +17,7 @@
 
 import {assertExists} from '../base/logging';
 import {duration, time} from '../base/time';
+import {PanelSize} from '../frontend/panel';
 import {NewTrackArgs} from '../frontend/track';
 import {SliceRect} from '../public';
 import {EngineProxy} from '../trace_processor/engine';
@@ -100,8 +101,8 @@
     return await this.controller.onBoundsChange(start, end, resolution);
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
-    this.track.renderCanvas(ctx);
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
+    this.track.renderCanvas(ctx, size);
   }
 }
 
@@ -133,7 +134,7 @@
     this.trackKey = args.trackKey;
   }
 
-  abstract renderCanvas(ctx: CanvasRenderingContext2D): void;
+  abstract renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void;
 
   getSliceRect(_tStart: time, _tEnd: time, _depth: number): SliceRect
       |undefined {
diff --git a/ui/src/common/track_helper.ts b/ui/src/common/track_helper.ts
index f634627..8990a44 100644
--- a/ui/src/common/track_helper.ts
+++ b/ui/src/common/track_helper.ts
@@ -17,6 +17,7 @@
 import {duration, Time, time} from '../base/time';
 import {raf} from '../core/raf_scheduler';
 import {globals} from '../frontend/globals';
+import {PanelSize} from '../frontend/panel';
 import {SliceRect, Track, TrackContext} from '../public';
 
 import {TrackData} from './track_data';
@@ -89,14 +90,14 @@
   abstract onBoundsChange(start: time, end: time, resolution: duration):
       Promise<Data>;
 
-  abstract renderCanvas(ctx: CanvasRenderingContext2D): void;
+  abstract renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void;
 
-  render(ctx: CanvasRenderingContext2D): void {
+  render(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     if (this.shouldLoadNewData()) {
       this.loadData();
     }
 
-    this.renderCanvas(ctx);
+    this.renderCanvas(ctx, size);
   }
 
   private loadData(): void {
diff --git a/ui/src/frontend/base_counter_track.ts b/ui/src/frontend/base_counter_track.ts
index ae7145d..5081cb7 100644
--- a/ui/src/frontend/base_counter_track.ts
+++ b/ui/src/frontend/base_counter_track.ts
@@ -29,6 +29,7 @@
 
 import {checkerboardExcept} from './checkerboard';
 import {globals} from './globals';
+import {PanelSize} from './panel';
 import {constraintsToQuerySuffix} from './sql_utils';
 import {NewTrackArgs, TrackBase} from './track';
 import {CacheKey, TrackCache} from './track_cache';
@@ -175,11 +176,10 @@
     ];
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D) {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize) {
     const {
       visibleTimeScale: timeScale,
       visibleWindowTime: vizTime,
-      windowSpan,
     } = globals.frontendLocalState;
 
     {
@@ -237,7 +237,7 @@
     }
 
     const effectiveHeight = this.getHeight() - MARGIN_TOP;
-    const endPx = windowSpan.end;
+    const endPx = size.width;
     const zeroY = MARGIN_TOP + effectiveHeight / (minimumValue < 0 ? 2 : 1);
 
     // Quantize the Y axis to quarters of powers of tens (7.5K, 10K, 12.5K).
@@ -373,8 +373,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         timeScale.timeToPx(this.countersKey.start),
         timeScale.timeToPx(this.countersKey.end));
   }
diff --git a/ui/src/frontend/base_slice_track.ts b/ui/src/frontend/base_slice_track.ts
index 2c873da..95855cf 100644
--- a/ui/src/frontend/base_slice_track.ts
+++ b/ui/src/frontend/base_slice_track.ts
@@ -36,6 +36,7 @@
 
 import {checkerboardExcept} from './checkerboard';
 import {globals} from './globals';
+import {PanelSize} from './panel';
 import {DEFAULT_SLICE_LAYOUT, SliceLayout} from './slice_layout';
 import {constraintsToQuerySuffix} from './sql_utils';
 import {NewTrackArgs, TrackBase} from './track';
@@ -325,7 +326,7 @@
     return `${size}px Roboto Condensed`;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO(hjd): fonts and colors should come from the CSS and not hardcoded
     // here.
     const {
@@ -545,8 +546,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        timeScale.hpTimeToPx(vizTime.start),
-        timeScale.hpTimeToPx(vizTime.end),
+        0,
+        size.width,
         timeScale.timeToPx(this.slicesKey.start),
         timeScale.timeToPx(this.slicesKey.end));
 
diff --git a/ui/src/frontend/notes_panel.ts b/ui/src/frontend/notes_panel.ts
index 1904f32..1d7589c 100644
--- a/ui/src/frontend/notes_panel.ts
+++ b/ui/src/frontend/notes_panel.ts
@@ -215,7 +215,7 @@
     ctx.strokeStyle = color;
     const topOffset = 10;
     // Don't draw in the track shell section.
-    if (x >= globals.frontendLocalState.windowSpan.start + TRACK_SHELL_WIDTH) {
+    if (x >= TRACK_SHELL_WIDTH) {
       // Draw left triangle.
       ctx.beginPath();
       ctx.moveTo(x, topOffset);
@@ -235,8 +235,7 @@
     ctx.stroke();
 
     // Start line after track shell section, join triangles.
-    const startDraw = Math.max(
-        x, globals.frontendLocalState.windowSpan.start + TRACK_SHELL_WIDTH);
+    const startDraw = Math.max(x, TRACK_SHELL_WIDTH);
     ctx.beginPath();
     ctx.moveTo(startDraw, topOffset);
     ctx.lineTo(xEnd, topOffset);
diff --git a/ui/src/frontend/slice_track.ts b/ui/src/frontend/slice_track.ts
index 0264d07..685ff8c 100644
--- a/ui/src/frontend/slice_track.ts
+++ b/ui/src/frontend/slice_track.ts
@@ -24,6 +24,7 @@
 import {CROP_INCOMPLETE_SLICE_FLAG} from './base_slice_track';
 import {checkerboardExcept} from './checkerboard';
 import {globals} from './globals';
+import {PanelSize} from './panel';
 
 export const SLICE_TRACK_KIND = 'ChromeSliceTrack';
 const SLICE_HEIGHT = 18;
@@ -76,21 +77,20 @@
     return '12px Roboto Condensed';
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO: fonts and colors should come from the CSS and not hardcoded here.
     const data = this.data;
     if (data === undefined) return;  // Can't possibly draw anything.
 
-    const {visibleTimeSpan, visibleWindowTime, visibleTimeScale, windowSpan} =
-        globals.frontendLocalState;
+    const {visibleTimeSpan, visibleTimeScale} = globals.frontendLocalState;
 
     // If the cached trace slices don't fully cover the visible time range,
     // show a gray rectangle with a "Loading..." label.
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        visibleTimeScale.hpTimeToPx(visibleWindowTime.start),
-        visibleTimeScale.hpTimeToPx(visibleWindowTime.end),
+        0,
+        size.width,
         visibleTimeScale.timeToPx(data.start),
         visibleTimeScale.timeToPx(data.end),
     );
@@ -125,7 +125,7 @@
         continue;
       }
 
-      const pxEnd = windowSpan.end;
+      const pxEnd = size.width;
       const left = Math.max(visibleTimeScale.timeToPx(tStart), 0);
       const right = Math.min(visibleTimeScale.timeToPx(tEnd), pxEnd);
 
diff --git a/ui/src/frontend/track.ts b/ui/src/frontend/track.ts
index 7fcce0b..3cc79f1 100644
--- a/ui/src/frontend/track.ts
+++ b/ui/src/frontend/track.ts
@@ -18,6 +18,7 @@
 import {SliceRect, Track, TrackContext} from '../public';
 import {EngineProxy} from '../trace_processor/engine';
 
+import {PanelSize} from './panel';
 // Args passed to the track constructors when creating a new track.
 export interface NewTrackArgs {
   trackKey: string;
@@ -40,7 +41,8 @@
   // this object is removed.
   onDestroy() {}
 
-  protected abstract renderCanvas(ctx: CanvasRenderingContext2D): void;
+  protected abstract renderCanvas(
+      ctx: CanvasRenderingContext2D, size: PanelSize): void;
 
   getHeight(): number {
     return 40;
@@ -62,8 +64,8 @@
 
   onFullRedraw(): void {}
 
-  render(ctx: CanvasRenderingContext2D) {
-    this.renderCanvas(ctx);
+  render(ctx: CanvasRenderingContext2D, size: PanelSize) {
+    this.renderCanvas(ctx, size);
   }
 
   // Returns a place where a given slice should be drawn. Should be implemented
diff --git a/ui/src/frontend/track_group_panel.ts b/ui/src/frontend/track_group_panel.ts
index ec6e7e6..6b69607 100644
--- a/ui/src/frontend/track_group_panel.ts
+++ b/ui/src/frontend/track_group_panel.ts
@@ -237,7 +237,8 @@
     ctx.save();
     ctx.translate(this.shellWidth, 0);
     if (this.summaryTrack) {
-      this.summaryTrack.render(ctx);
+      const trackSize = {...size, width: size.width - this.shellWidth};
+      this.summaryTrack.render(ctx, trackSize);
     }
     ctx.restore();
 
diff --git a/ui/src/frontend/track_panel.ts b/ui/src/frontend/track_panel.ts
index dec3a65..afd58c6 100644
--- a/ui/src/frontend/track_panel.ts
+++ b/ui/src/frontend/track_panel.ts
@@ -444,7 +444,8 @@
 
     ctx.translate(TRACK_SHELL_WIDTH, 0);
     if (this.track !== undefined) {
-      this.track.render(ctx);
+      const trackSize = {...size, width: size.width - TRACK_SHELL_WIDTH};
+      this.track.render(ctx, trackSize);
     } else {
       checkerboard(ctx, size.height, 0, size.width - TRACK_SHELL_WIDTH);
     }
diff --git a/ui/src/public/index.ts b/ui/src/public/index.ts
index 81f9225..7a2aaf2 100644
--- a/ui/src/public/index.ts
+++ b/ui/src/public/index.ts
@@ -17,6 +17,7 @@
 import {Hotkey} from '../base/hotkeys';
 import {duration, time} from '../base/time';
 import {ColorScheme} from '../common/colorizer';
+import {PanelSize} from '../frontend/panel';
 import {Store} from '../frontend/store';
 import {EngineProxy} from '../trace_processor/engine';
 
@@ -172,7 +173,7 @@
 
 export interface Track {
   onCreate(ctx: TrackContext): void;
-  render(ctx: CanvasRenderingContext2D): void;
+  render(ctx: CanvasRenderingContext2D, size: PanelSize): void;
   onFullRedraw(): void;
   getSliceRect(tStart: time, tEnd: time, depth: number): SliceRect|undefined;
   getHeight(): number;
diff --git a/ui/src/tracks/android_log/index.ts b/ui/src/tracks/android_log/index.ts
index 2f78a57..04237b6 100644
--- a/ui/src/tracks/android_log/index.ts
+++ b/ui/src/tracks/android_log/index.ts
@@ -21,6 +21,7 @@
 import {LIMIT, TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {
   Plugin,
@@ -107,8 +108,8 @@
     super(args);
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
-    const {visibleTimeScale, windowSpan} = globals.frontendLocalState;
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
+    const {visibleTimeScale} = globals.frontendLocalState;
 
     const data = this.data();
 
@@ -116,16 +117,9 @@
 
     const dataStartPx = visibleTimeScale.timeToPx(data.start);
     const dataEndPx = visibleTimeScale.timeToPx(data.end);
-    const visibleStartPx = windowSpan.start;
-    const visibleEndPx = windowSpan.end;
 
     checkerboardExcept(
-        ctx,
-        this.getHeight(),
-        visibleStartPx,
-        visibleEndPx,
-        dataStartPx,
-        dataEndPx);
+        ctx, this.getHeight(), 0, size.width, dataStartPx, dataEndPx);
 
     const quantWidth =
         Math.max(EVT_PX, visibleTimeScale.durationToPx(data.resolution));
diff --git a/ui/src/tracks/counter/index.ts b/ui/src/tracks/counter/index.ts
index 4f2b7f4..f9b61a5 100644
--- a/ui/src/tracks/counter/index.ts
+++ b/ui/src/tracks/counter/index.ts
@@ -29,6 +29,7 @@
 } from '../../common/track_helper';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {
   EngineProxy,
   LONG,
@@ -348,11 +349,10 @@
     );
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO: fonts and colors should come from the CSS and not hardcoded here.
     const {
       visibleTimeScale: timeScale,
-      windowSpan,
     } = globals.frontendLocalState;
     const data = this.data;
 
@@ -389,7 +389,7 @@
       minimumValue = data.minimumRate;
     }
 
-    const endPx = windowSpan.end;
+    const endPx = size.width;
     const zeroY = MARGIN_TOP + RECT_HEIGHT / (minimumValue < 0 ? 2 : 1);
 
     // Quantize the Y axis to quarters of powers of tens (7.5K, 10K, 12.5K).
@@ -550,8 +550,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         timeScale.timeToPx(data.start),
         timeScale.timeToPx(data.end));
   }
diff --git a/ui/src/tracks/cpu_freq/index.ts b/ui/src/tracks/cpu_freq/index.ts
index aa421f6..06f3087 100644
--- a/ui/src/tracks/cpu_freq/index.ts
+++ b/ui/src/tracks/cpu_freq/index.ts
@@ -27,6 +27,7 @@
 import {TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {
   Plugin,
@@ -288,12 +289,11 @@
     return MARGIN_TOP + RECT_HEIGHT;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO: fonts and colors should come from the CSS and not hardcoded here.
     const {
       visibleTimeScale,
       visibleWindowTime,
-      windowSpan,
     } = globals.frontendLocalState;
     const data = this.data();
 
@@ -307,7 +307,7 @@
     assertTrue(data.timestamps.length === data.maxFreqKHz.length);
     assertTrue(data.timestamps.length === data.lastIdleValues.length);
 
-    const endPx = windowSpan.end;
+    const endPx = size.width;
     const zeroY = MARGIN_TOP + RECT_HEIGHT;
 
     // Quantize the Y axis to quarters of powers of tens (7.5K, 10K, 12.5K).
@@ -456,8 +456,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         visibleTimeScale.timeToPx(data.start),
         visibleTimeScale.timeToPx(data.end));
   }
diff --git a/ui/src/tracks/cpu_profile/index.ts b/ui/src/tracks/cpu_profile/index.ts
index 59ad373..df0916b 100644
--- a/ui/src/tracks/cpu_profile/index.ts
+++ b/ui/src/tracks/cpu_profile/index.ts
@@ -24,6 +24,7 @@
 } from '../../common/track_adapter';
 import {TrackData} from '../../common/track_data';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {TimeScale} from '../../frontend/time_scale';
 import {NewTrackArgs} from '../../frontend/track';
 import {
@@ -102,7 +103,7 @@
     return MARGIN_TOP + RECT_HEIGHT - 1;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, _size: PanelSize): void {
     const {
       visibleTimeScale: timeScale,
     } = globals.frontendLocalState;
diff --git a/ui/src/tracks/cpu_slices/index.ts b/ui/src/tracks/cpu_slices/index.ts
index 0e9c470..f4b2830 100644
--- a/ui/src/tracks/cpu_slices/index.ts
+++ b/ui/src/tracks/cpu_slices/index.ts
@@ -34,6 +34,7 @@
 import {TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {
   EngineProxy,
@@ -217,9 +218,9 @@
     return TRACK_HEIGHT;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO: fonts and colors should come from the CSS and not hardcoded here.
-    const {visibleTimeScale, windowSpan} = globals.frontendLocalState;
+    const {visibleTimeScale} = globals.frontendLocalState;
     const data = this.data();
 
     if (data === undefined) return;  // Can't possibly draw anything.
@@ -229,8 +230,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         visibleTimeScale.timeToPx(data.start),
         visibleTimeScale.timeToPx(data.end));
 
diff --git a/ui/src/tracks/ftrace/index.ts b/ui/src/tracks/ftrace/index.ts
index 75c741e..6ae8474 100644
--- a/ui/src/tracks/ftrace/index.ts
+++ b/ui/src/tracks/ftrace/index.ts
@@ -18,6 +18,7 @@
 import {TrackHelperLEGACY} from '../../common/track_helper';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {
   EngineProxy,
   Plugin,
@@ -89,10 +90,9 @@
     return result;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     const {
       visibleTimeScale,
-      windowSpan,
     } = globals.frontendLocalState;
 
     const data = this.data;
@@ -101,16 +101,9 @@
 
     const dataStartPx = visibleTimeScale.timeToPx(data.start);
     const dataEndPx = visibleTimeScale.timeToPx(data.end);
-    const visibleStartPx = windowSpan.start;
-    const visibleEndPx = windowSpan.end;
 
     checkerboardExcept(
-        ctx,
-        this.getHeight(),
-        visibleStartPx,
-        visibleEndPx,
-        dataStartPx,
-        dataEndPx);
+        ctx, this.getHeight(), 0, size.width, dataStartPx, dataEndPx);
 
     const diamondSideLen = RECT_HEIGHT / Math.sqrt(2);
 
diff --git a/ui/src/tracks/perf_samples_profile/index.ts b/ui/src/tracks/perf_samples_profile/index.ts
index dd30045..a78e36d 100644
--- a/ui/src/tracks/perf_samples_profile/index.ts
+++ b/ui/src/tracks/perf_samples_profile/index.ts
@@ -24,6 +24,7 @@
 import {TrackData} from '../../common/track_data';
 import {FLAMEGRAPH_HOVERED_COLOR} from '../../frontend/flamegraph';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {TimeScale} from '../../frontend/time_scale';
 import {NewTrackArgs} from '../../frontend/track';
 import {
@@ -99,7 +100,7 @@
     return MARGIN_TOP + RECT_HEIGHT - 1;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, _size: PanelSize): void {
     const {
       visibleTimeScale,
     } = globals.frontendLocalState;
diff --git a/ui/src/tracks/process_summary/process_scheduling_track.ts b/ui/src/tracks/process_summary/process_scheduling_track.ts
index a955278..455cac5 100644
--- a/ui/src/tracks/process_summary/process_scheduling_track.ts
+++ b/ui/src/tracks/process_summary/process_scheduling_track.ts
@@ -28,6 +28,7 @@
 import {TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {
   LONG,
@@ -200,11 +201,10 @@
     return TRACK_HEIGHT;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     // TODO: fonts and colors should come from the CSS and not hardcoded here.
     const {
       visibleTimeScale,
-      visibleWindowTime,
       visibleTimeSpan,
     } = globals.frontendLocalState;
     const data = this.data();
@@ -216,8 +216,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        visibleTimeScale.hpTimeToPx(visibleWindowTime.start),
-        visibleTimeScale.hpTimeToPx(visibleWindowTime.end),
+        0,
+        size.width,
         visibleTimeScale.timeToPx(data.start),
         visibleTimeScale.timeToPx(data.end));
 
diff --git a/ui/src/tracks/process_summary/process_summary_track.ts b/ui/src/tracks/process_summary/process_summary_track.ts
index ee0bcc8..383dcb3 100644
--- a/ui/src/tracks/process_summary/process_summary_track.ts
+++ b/ui/src/tracks/process_summary/process_summary_track.ts
@@ -20,6 +20,7 @@
 import {LIMIT, TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {NUM} from '../../trace_processor/query_result';
 
@@ -150,10 +151,9 @@
     return TRACK_HEIGHT;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     const {
       visibleTimeScale,
-      windowSpan,
     } = globals.frontendLocalState;
     const data = this.data();
     if (data === undefined) return;  // Can't possibly draw anything.
@@ -161,8 +161,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         visibleTimeScale.timeToPx(data.start),
         visibleTimeScale.timeToPx(data.end));
 
@@ -171,8 +171,8 @@
 
   // TODO(dproy): Dedup with CPU slices.
   renderSummary(ctx: CanvasRenderingContext2D, data: Data): void {
-    const {visibleTimeScale, windowSpan} = globals.frontendLocalState;
-    const startPx = windowSpan.start;
+    const {visibleTimeScale} = globals.frontendLocalState;
+    const startPx = 0;
     const bottomY = TRACK_HEIGHT;
 
     let lastX = startPx;
diff --git a/ui/src/tracks/thread_state/index.ts b/ui/src/tracks/thread_state/index.ts
index 7544ddb..074025e 100644
--- a/ui/src/tracks/thread_state/index.ts
+++ b/ui/src/tracks/thread_state/index.ts
@@ -28,6 +28,7 @@
 import {TrackData} from '../../common/track_data';
 import {checkerboardExcept} from '../../frontend/checkerboard';
 import {globals} from '../../frontend/globals';
+import {PanelSize} from '../../frontend/panel';
 import {NewTrackArgs} from '../../frontend/track';
 import {
   Plugin,
@@ -187,11 +188,10 @@
     return 2 * MARGIN_TOP + RECT_HEIGHT;
   }
 
-  renderCanvas(ctx: CanvasRenderingContext2D): void {
+  renderCanvas(ctx: CanvasRenderingContext2D, size: PanelSize): void {
     const {
       visibleTimeScale: timeScale,
       visibleTimeSpan,
-      windowSpan,
     } = globals.frontendLocalState;
     const data = this.data();
     const charWidth = ctx.measureText('dbpqaouk').width / 8;
@@ -205,8 +205,8 @@
     checkerboardExcept(
         ctx,
         this.getHeight(),
-        windowSpan.start,
-        windowSpan.end,
+        0,
+        size.width,
         timeScale.timeToPx(data.start),
         timeScale.timeToPx(data.end),
     );
@@ -257,7 +257,7 @@
           const rectStart =
               Math.max(0 - EXCESS_WIDTH, timeScale.timeToPx(tStart));
           const rectEnd =
-              Math.min(windowSpan.end + EXCESS_WIDTH, timeScale.timeToPx(tEnd));
+              Math.min(size.width + EXCESS_WIDTH, timeScale.timeToPx(tEnd));
           ctx.strokeStyle = colorScheme.base.cssString;
           ctx.beginPath();
           ctx.lineWidth = 3;