Introduce bottom controls to CC and let it respond to scrolling

cc/input/top_controls_manager.h

Index: cc/input/top_controls_manager.h
diff --git a/cc/input/top_controls_manager.h b/cc/input/top_controls_manager.h
index 4ec45776e99e9f7452a65fc2762dec48f5d68213..35b24d991c48df8940b3731809319ce4c67ca933 100644
--- a/cc/input/top_controls_manager.h
+++ b/cc/input/top_controls_manager.h
@@ -40,6 +40,9 @@ class CC_EXPORT TopControlsManager
   float ContentTopOffset() const;
   float TopControlsShownRatio() const;
   float TopControlsHeight() const;
+  float BottomControlsHeight() const;
+  float BottomControlsOffset() const;

[bokan, 2016/06/30 12:31:21]

Please match the exiting convention:

BottomControlsOffset -> ControlsBottomOffset
BottomContentOffset -> ContentBottomOffset

[Ian Wen, 2016/07/01 02:51:44]

Done.

+  float BottomContentOffset() const;
 
   bool has_animation() const { return animation_direction_ != NO_ANIMATION; }
   AnimationDirection animation_direction() { return animation_direction_; }