Re-implement overscan & Implement Display Rotation

ui/aura/root_window_host.h

Index: ui/aura/root_window_host.h
diff --git a/ui/aura/root_window_host.h b/ui/aura/root_window_host.h
index 2a07cea020f3c21064e9ef120c8807d3f3d7f495..424968cd988843c1c8a5189d19038ee868d94553 100644
--- a/ui/aura/root_window_host.h
+++ b/ui/aura/root_window_host.h
@@ -15,6 +15,7 @@
 class SkCanvas;
 
 namespace gfx {
+class Insets;
 class Point;
 class Rect;
 class Size;
@@ -60,6 +61,11 @@ class AURA_EXPORT RootWindowHost {
   virtual gfx::Rect GetBounds() const = 0;
   virtual void SetBounds(const gfx::Rect& bounds) = 0;
 
+  // Sets/Gets the insets that specifies the effective root window area
+  // in the host window.
+  virtual gfx::Insets GetInsets() const = 0;
+  virtual void SetInsets(const gfx::Insets& insets) = 0;
+
   // Returns the location of the RootWindow on native screen.
   virtual gfx::Point GetLocationOnNativeScreen() const = 0;