Handle resize corner layout entirely in the platform BrowserWindow*/BrowserView* code...

chrome/browser/renderer_host/render_widget_host.h

Index: chrome/browser/renderer_host/render_widget_host.h
===================================================================
--- chrome/browser/renderer_host/render_widget_host.h	(revision 65756)
+++ chrome/browser/renderer_host/render_widget_host.h	(working copy)
@@ -19,6 +19,7 @@
 #include "chrome/common/native_web_keyboard_event.h"
 #include "chrome/common/property_bag.h"
 #include "gfx/native_widget_types.h"
+#include "gfx/rect.h"
 #include "gfx/size.h"
 #include "ipc/ipc_channel.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebInputEvent.h"
@@ -363,10 +364,6 @@
   // Cancels an ongoing composition.
   void ImeCancelComposition();
 
-  // This is for derived classes to give us access to the resizer rect.
-  // And to also expose it to the RenderWidgetHostView.
-  virtual gfx::Rect GetRootWindowResizerRect() const;
-
   // Makes an IPC call to toggle the spelling panel.
   void ToggleSpellPanel(bool is_currently_visible);
 
@@ -575,6 +572,10 @@
   // The current size of the RenderWidget.
   gfx::Size current_size_;
 
+  // The current reserved area of the RenderWidget where contents should not be
+  // rendered to draw the resize corner, sidebar mini tabs etc.
+  gfx::Rect current_reserved_rect_;
+
   // The size we last sent as requested size to the renderer. |current_size_|
   // is only updated once the resize message has been ack'd. This on the other
   // hand is updated when the resize message is sent. This is very similar to
@@ -582,6 +583,11 @@
   // or height zero, which is why we need this too.
   gfx::Size in_flight_size_;
 
+  // The reserved area we last sent to the renderer. |current_reserved_rect_|
+  // is only updated once the resize message has been ack'd. This on the other
+  // hand is updated when the resize message is sent.
+  gfx::Rect in_flight_reserved_rect_;
+
   // True if a mouse move event was sent to the render view and we are waiting
   // for a corresponding ViewHostMsg_HandleInputEvent_ACK message.
   bool mouse_move_pending_;