cc : Make CallFunctionForSubtree on impl use layer iterator

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 cc8d12363b1d339afe60882cfe9ca96e20768429..1d1a33bef34771057be7922477a2a0e7409a3e94 100644
--- a/cc/debug/debug_rect_history.cc
+++ b/cc/debug/debug_rect_history.cc
@@ -158,9 +158,9 @@ void DebugRectHistory::SaveScreenSpaceRects(
 }
 
 void DebugRectHistory::SaveTouchEventHandlerRects(LayerImpl* layer) {

[ajuma, 2016/04/01 13:38:14]

Can this be changed to take a tree instead of a layer? Now we're implicitly
assuming it's only ever called on the root layer (which it is), but it'd be good
to make it explicit that this affects the entire tree. Same comment for the
other methods below.

[jaydasika, 2016/04/01 17:01:24]

Done.

-  LayerTreeHostCommon::CallFunctionForSubtree(layer, [this](LayerImpl* layer) {
-    SaveTouchEventHandlerRectsCallback(layer);
-  });
+  LayerTreeHostCommon::CallFunctionForEveryLayer(
+      layer->layer_tree_impl(),
+      [this](LayerImpl* layer) { SaveTouchEventHandlerRectsCallback(layer); });
 }
 
 void DebugRectHistory::SaveTouchEventHandlerRectsCallback(LayerImpl* layer) {
@@ -197,9 +197,9 @@ void DebugRectHistory::SaveWheelEventHandlerRects(LayerImpl* root_layer) {
 }
 
 void DebugRectHistory::SaveScrollEventHandlerRects(LayerImpl* layer) {
-  LayerTreeHostCommon::CallFunctionForSubtree(layer, [this](LayerImpl* layer) {
-    SaveScrollEventHandlerRectsCallback(layer);
-  });
+  LayerTreeHostCommon::CallFunctionForEveryLayer(
+      layer->layer_tree_impl(),
+      [this](LayerImpl* layer) { SaveScrollEventHandlerRectsCallback(layer); });
 }
 
 void DebugRectHistory::SaveScrollEventHandlerRectsCallback(LayerImpl* layer) {
@@ -213,9 +213,9 @@ void DebugRectHistory::SaveScrollEventHandlerRectsCallback(LayerImpl* layer) {
 }
 
 void DebugRectHistory::SaveNonFastScrollableRects(LayerImpl* layer) {
-  LayerTreeHostCommon::CallFunctionForSubtree(layer, [this](LayerImpl* layer) {
-    SaveNonFastScrollableRectsCallback(layer);
-  });
+  LayerTreeHostCommon::CallFunctionForEveryLayer(
+      layer->layer_tree_impl(),
+      [this](LayerImpl* layer) { SaveNonFastScrollableRectsCallback(layer); });
 }
 
 void DebugRectHistory::SaveNonFastScrollableRectsCallback(LayerImpl* layer) {