BoxDecoration API changes: backgroundColor -> color et al (#9648)

backgroundColor -> color
backgroundImage -> image
BackgroundImage -> DecorationImage
diff --git a/examples/layers/rendering/flex_layout.dart b/examples/layers/rendering/flex_layout.dart
index 7175341..dc38d85 100644
--- a/examples/layers/rendering/flex_layout.dart
+++ b/examples/layers/rendering/flex_layout.dart
@@ -19,18 +19,18 @@
     final RenderFlex row = new RenderFlex(crossAxisAlignment: crossAxisAlignment, textBaseline: TextBaseline.alphabetic);
     style = const TextStyle(fontSize: 15.0, color: const Color(0xFF000000));
     row.add(new RenderDecoratedBox(
-      decoration: const BoxDecoration(backgroundColor: const Color(0x7FFFCCCC)),
+      decoration: const BoxDecoration(color: const Color(0x7FFFCCCC)),
       child: new RenderParagraph(new TextSpan(style: style, text: 'foo foo foo'))
     ));
     style = const TextStyle(fontSize: 10.0, color: const Color(0xFF000000));
     row.add(new RenderDecoratedBox(
-      decoration: const BoxDecoration(backgroundColor: const Color(0x7FCCFFCC)),
+      decoration: const BoxDecoration(color: const Color(0x7FCCFFCC)),
       child: new RenderParagraph(new TextSpan(style: style, text: 'foo foo foo'))
     ));
     final RenderFlex subrow = new RenderFlex(crossAxisAlignment: crossAxisAlignment, textBaseline: TextBaseline.alphabetic);
     style = const TextStyle(fontSize: 25.0, color: const Color(0xFF000000));
     subrow.add(new RenderDecoratedBox(
-      decoration: const BoxDecoration(backgroundColor: const Color(0x7FCCCCFF)),
+      decoration: const BoxDecoration(color: const Color(0x7FCCCCFF)),
       child: new RenderParagraph(new TextSpan(style: style, text: 'foo foo foo foo'))
     ));
     subrow.add(new RenderSolidColorBox(const Color(0x7FCCFFFF), desiredSize: const Size(30.0, 40.0)));
@@ -67,7 +67,7 @@
   addJustificationRow(MainAxisAlignment.spaceAround);
 
   final RenderDecoratedBox root = new RenderDecoratedBox(
-    decoration: const BoxDecoration(backgroundColor: const Color(0xFFFFFFFF)),
+    decoration: const BoxDecoration(color: const Color(0xFFFFFFFF)),
     child: new RenderPadding(child: table, padding: const EdgeInsets.symmetric(vertical: 50.0))
   );
 
diff --git a/examples/layers/rendering/spinning_square.dart b/examples/layers/rendering/spinning_square.dart
index fcf97e6..a7f5623 100644
--- a/examples/layers/rendering/spinning_square.dart
+++ b/examples/layers/rendering/spinning_square.dart
@@ -20,7 +20,7 @@
 void main() {
   // We first create a render object that represents a green box.
   final RenderBox green = new RenderDecoratedBox(
-    decoration: const BoxDecoration(backgroundColor: const Color(0xFF00FF00))
+    decoration: const BoxDecoration(color: const Color(0xFF00FF00))
   );
   // Second, we wrap that green box in a render object that forces the green box
   // to have a specific size.
diff --git a/examples/layers/rendering/src/sector_layout.dart b/examples/layers/rendering/src/sector_layout.dart
index 6904b4a..c2adb00 100644
--- a/examples/layers/rendering/src/sector_layout.dart
+++ b/examples/layers/rendering/src/sector_layout.dart
@@ -166,9 +166,9 @@
     if (_decoration == null)
       return;
 
-    if (_decoration.backgroundColor != null) {
+    if (_decoration.color != null) {
       final Canvas canvas = context.canvas;
-      final Paint paint = new Paint()..color = _decoration.backgroundColor;
+      final Paint paint = new Paint()..color = _decoration.color;
       final Path path = new Path();
       final double outerRadius = (parentData.radius + deltaRadius);
       final Rect outerBounds = new Rect.fromLTRB(offset.dx-outerRadius, offset.dy-outerRadius, offset.dx+outerRadius, offset.dy+outerRadius);
@@ -558,7 +558,7 @@
   RenderSolidColor(this.backgroundColor, {
     this.desiredDeltaRadius: double.INFINITY,
     this.desiredDeltaTheta: kTwoPi
-  }) : super(new BoxDecoration(backgroundColor: backgroundColor));
+  }) : super(new BoxDecoration(color: backgroundColor));
 
   double desiredDeltaRadius;
   double desiredDeltaTheta;
@@ -578,9 +578,9 @@
   @override
   void handleEvent(PointerEvent event, HitTestEntry entry) {
     if (event is PointerDownEvent) {
-      decoration = const BoxDecoration(backgroundColor: const Color(0xFFFF0000));
+      decoration = const BoxDecoration(color: const Color(0xFFFF0000));
     } else if (event is PointerUpEvent) {
-      decoration = new BoxDecoration(backgroundColor: backgroundColor);
+      decoration = new BoxDecoration(color: backgroundColor);
     }
   }
 }
diff --git a/examples/layers/rendering/src/solid_color_box.dart b/examples/layers/rendering/src/solid_color_box.dart
index c4e51c7..5ea81e3 100644
--- a/examples/layers/rendering/src/solid_color_box.dart
+++ b/examples/layers/rendering/src/solid_color_box.dart
@@ -10,7 +10,7 @@
   final Color backgroundColor;
 
   RenderSolidColorBox(this.backgroundColor, { this.desiredSize: Size.infinite })
-      : super(decoration: new BoxDecoration(backgroundColor: backgroundColor));
+      : super(decoration: new BoxDecoration(color: backgroundColor));
 
   @override
   double computeMinIntrinsicWidth(double height) {
@@ -40,9 +40,9 @@
   @override
   void handleEvent(PointerEvent event, BoxHitTestEntry entry) {
     if (event is PointerDownEvent) {
-      decoration = const BoxDecoration(backgroundColor: const Color(0xFFFF0000));
+      decoration = const BoxDecoration(color: const Color(0xFFFF0000));
     } else if (event is PointerUpEvent) {
-      decoration = new BoxDecoration(backgroundColor: backgroundColor);
+      decoration = new BoxDecoration(color: backgroundColor);
     }
   }
 }
diff --git a/examples/layers/services/isolate.dart b/examples/layers/services/isolate.dart
index c0b316c..b325d7d 100644
--- a/examples/layers/services/isolate.dart
+++ b/examples/layers/services/isolate.dart
@@ -244,9 +244,7 @@
             child: new Container(
               width: 120.0,
               height: 120.0,
-              decoration: const BoxDecoration(
-                backgroundColor: const Color(0xFF882222)
-              )
+              color: const Color(0xFF882222),
             )
           ),
           new Opacity(
diff --git a/examples/layers/widgets/media_query.dart b/examples/layers/widgets/media_query.dart
index d7aec23..d96017e 100644
--- a/examples/layers/widgets/media_query.dart
+++ b/examples/layers/widgets/media_query.dart
@@ -17,9 +17,7 @@
           width: 32.0,
           height: 32.0,
           margin: const EdgeInsets.all(8.0),
-          decoration: new BoxDecoration(
-            backgroundColor: Colors.lightBlueAccent.shade100
-          )
+          color: Colors.lightBlueAccent.shade100,
         ),
         new Text(name)
       ]
@@ -39,9 +37,7 @@
         children: <Widget>[
           new Expanded(
             child: new Container(
-              decoration: new BoxDecoration(
-                backgroundColor: Colors.lightBlueAccent.shade100
-              )
+              color: Colors.lightBlueAccent.shade100,
             )
           ),
           new Container(
diff --git a/examples/layers/widgets/spinning_mixed.dart b/examples/layers/widgets/spinning_mixed.dart
index 2a1c06d..71ba4da 100644
--- a/examples/layers/widgets/spinning_mixed.dart
+++ b/examples/layers/widgets/spinning_mixed.dart
@@ -25,7 +25,7 @@
   Widget build(BuildContext context) {
     return new Expanded(
       child: new Container(
-        decoration: new BoxDecoration(backgroundColor: color)
+        color: color,
       )
     );
   }
diff --git a/examples/layers/widgets/spinning_square.dart b/examples/layers/widgets/spinning_square.dart
index e9a4f7b..be59f1c 100644
--- a/examples/layers/widgets/spinning_square.dart
+++ b/examples/layers/widgets/spinning_square.dart
@@ -37,9 +37,7 @@
       child: new Container(
         width: 200.0,
         height: 200.0,
-        decoration: const BoxDecoration(
-          backgroundColor: const Color(0xFF00FF00)
-        )
+        color: const Color(0xFF00FF00),
       )
     );
   }