Custom frame UI for platform apps on Windows.

content/browser/renderer_host/render_widget_host_view_win.h

Index: content/browser/renderer_host/render_widget_host_view_win.h
diff --git a/content/browser/renderer_host/render_widget_host_view_win.h b/content/browser/renderer_host/render_widget_host_view_win.h
index a4a6a056b5ce68d231901112385097ba82d54b71..2217be6d0497e6217614edfae5753236f49ccafd 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.h
+++ b/content/browser/renderer_host/render_widget_host_view_win.h
@@ -27,6 +27,7 @@
 #include "ui/base/win/ime_input.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/point.h"
+#include "ui/gfx/scoped_sk_region.h"
 #include "ui/gfx/surface/accelerated_surface_win.h"
 #include "webkit/glue/webcursor.h"
 
@@ -103,6 +104,7 @@ class RenderWidgetHostViewWin
     MSG_WM_DESTROY(OnDestroy)
     MSG_WM_PAINT(OnPaint)
     MSG_WM_NCPAINT(OnNCPaint)
+    MSG_WM_NCHITTEST(OnNCHitTest)
     MSG_WM_ERASEBKGND(OnEraseBkgnd)
     MSG_WM_SETCURSOR(OnSetCursor)
     MSG_WM_SETFOCUS(OnSetFocus)
@@ -227,6 +229,8 @@ class RenderWidgetHostViewWin
   virtual void AccessibilitySetTextSelection(
       int acc_obj_id, int start_offset, int end_offset) OVERRIDE;
 
+  virtual void SetTransparentRegion(SkRegion* region);
+
  protected:
   friend class RenderWidgetHostView;
 
@@ -241,6 +245,7 @@ class RenderWidgetHostViewWin
   void OnDestroy();
   void OnPaint(HDC unused_dc);
   void OnNCPaint(HRGN update_region);
+  LRESULT OnNCHitTest(const CPoint& pt);
   LRESULT OnEraseBkgnd(HDC dc);
   LRESULT OnSetCursor(HWND window, UINT hittest_code, UINT mouse_message_id);
   void OnSetFocus(HWND window);
@@ -546,6 +551,9 @@ class RenderWidgetHostViewWin
   // Set to true if we received a focus change after a WM_POINTERDOWN message.
   bool received_focus_change_after_pointer_down_;
 
+  // Region in which the view will be transparent to clicks.
+  gfx::ScopedSkRegion transparent_region_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewWin);
 };