Add quickstart instructions for UI

Change-Id: If0b54370f03a853f7fe16498448fd27a7b62ae57

docs/build-instructions.md

diff --git a/docs/build-instructions.md b/docs/build-instructions.md
index 823f05b..9ba085c 100644
--- a/docs/build-instructions.md
+++ b/docs/build-instructions.md
@@ -24,7 +24,7 @@
 **Standalone checkout**:  
 All dependent libraries are self-hosted and pulled through:
 ```
-$ tools/install-build-deps [--no-android]
+$ tools/install-build-deps [--no-android] [--ui]
 ```
 
 **Android tree**:  
@@ -51,6 +51,12 @@
 $ tools/ninja -C out/android
 ```
 
+To build the UI (remember to run `tools/install-build-deps --ui` first):
+
+```
+$ tools/ninja -C out/android ui
+```
+
 **Android tree**:  
 `$ mmma external/perfetto`
 or

ui/README.md

diff --git a/ui/README.md b/ui/README.md
new file mode 100644
index 0000000..5f51020
--- /dev/null
+++ b/ui/README.md
@@ -0,0 +1,24 @@
+# Perfetto UI
+
+Quick Start
+-----------
+Run:
+
+```
+$ git clone https://android.googlesource.com/platform/external/perfetto/
+$ cd perfetto
+$ tools/install-build-deps --no-android --ui
+$ tools/gn gen out/debug --args='is_debug=true is_clang=true'
+$ tools/ninja -C out/debug ui
+```
+
+For more details on `gn` configs see
+[Build Instructions](../docs/build-instructions.md).
+
+Finally run:
+
+```
+$ ./ui/run-dev-server
+```
+
+and navigate to `localhost:3000`.