Support for drawing a debug border around animated layers

cc/debug/debug_rect_history.cc

Index: cc/debug/debug_rect_history.cc
diff --git a/cc/debug/debug_rect_history.cc b/cc/debug/debug_rect_history.cc
index b972b321d8dbecedffc70f07cd95443b43413731..679beafdbb475f501f01adb4bd8c3cb68f3a5258 100644
--- a/cc/debug/debug_rect_history.cc
+++ b/cc/debug/debug_rect_history.cc
@@ -58,6 +58,9 @@ void DebugRectHistory::SaveDebugRectsForCurrentFrame(
 
   if (debug_state.show_non_occluding_rects)
     SaveNonOccludingRects(non_occluding_screen_space_rects);
+
+  if (debug_state.show_layer_animation_bounds_rects)
+    SaveLayerAnimationBoundsRects(render_surface_layer_list);
 }
 
 void DebugRectHistory::SavePaintRects(LayerImpl* layer) {
@@ -232,4 +235,28 @@ void DebugRectHistory::SaveNonFastScrollableRectsCallback(LayerImpl* layer) {
   }
 }
 
+void DebugRectHistory::SaveLayerAnimationBoundsRects(
+    const LayerImplList& render_surface_layer_list) {
+  typedef LayerIterator<LayerImpl,
+                        LayerImplList,
+                        RenderSurfaceImpl,
+                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list);
+  for (LayerIteratorType it =
+           LayerIteratorType::Begin(&render_surface_layer_list);
+       it != end; ++it) {
+    if (!it.represents_itself())
+      continue;
+    gfx::BoxF inflated_bounds;
+    if (!(*it)->GetAnimationBounds(&inflated_bounds))
+      continue;
+
+    debug_rects_.push_back(DebugRect(ANIMATION_BOUNDS_RECT_TYPE,
+                                     gfx::RectF(inflated_bounds.x(),
+                                                inflated_bounds.y(),
+                                                inflated_bounds.width(),
+                                                inflated_bounds.height())));
+  }
+}
+
 }  // namespace cc