Allow a Views client to provide a default frameview for window widgets.

ash/wm/modal_container_layout_manager.cc

Index: ash/wm/modal_container_layout_manager.cc
===================================================================
--- ash/wm/modal_container_layout_manager.cc	(revision 117168)
+++ ash/wm/modal_container_layout_manager.cc	(working copy)
@@ -4,10 +4,12 @@
 
 #include "ash/wm/modal_container_layout_manager.h"
 
+#include "ash/ash_switches.h"
 #include "ash/shell.h"
 #include "ash/wm/modality_event_filter.h"
 #include "ash/wm/window_util.h"
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
@@ -30,10 +32,18 @@
 
   // Overridden from views::View:
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
-    canvas->FillRect(SK_ColorBLACK, GetLocalBounds());
+    canvas->FillRect(GetOverlayColor(), GetLocalBounds());
   }
 
  private:
+  SkColor GetOverlayColor() {
+    if (CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kAuraGoogleDialogFrames)) {
+      return SK_ColorWHITE;
+    }
+    return SK_ColorBLACK;
+  }
+
   DISALLOW_COPY_AND_ASSIGN(ScreenView);
 };