Consolidate dialog style flags and strings; etc.

ash/wm/system_modal_container_layout_manager.cc

Index: ash/wm/system_modal_container_layout_manager.cc
diff --git a/ash/wm/system_modal_container_layout_manager.cc b/ash/wm/system_modal_container_layout_manager.cc
index 6d1a07576e075451afa35569ad0057b75e4a48f9..192d5ab726db1cea8d629612fa14bbd750cf9182 100644
--- a/ash/wm/system_modal_container_layout_manager.cc
+++ b/ash/wm/system_modal_container_layout_manager.cc
@@ -4,7 +4,6 @@
 
 #include "ash/wm/system_modal_container_layout_manager.h"
 
-#include "ash/ash_switches.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
@@ -19,10 +18,10 @@
 #include "ui/views/corewm/compound_event_filter.h"
 #include "ui/aura/window.h"
 #include "ui/base/events/event.h"
+#include "ui/base/ui_base_switches.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
-#include "ui/gfx/canvas.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
@@ -30,32 +29,6 @@
 namespace ash {
 namespace internal {
 
-namespace {
-
-class ModalBackgroundView : public views::View {
- public:
-  ModalBackgroundView() {}
-  virtual ~ModalBackgroundView() {}
-
-  // Overridden from views::View:
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
-    canvas->FillRect(GetLocalBounds(), GetOverlayColor());
-  }
-
- private:
-  SkColor GetOverlayColor() {
-    if (CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kAuraGoogleDialogFrames)) {
-      return SK_ColorWHITE;
-    }
-    return SK_ColorBLACK;
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(ModalBackgroundView);
-};
-
-}  // namespace
-
 ////////////////////////////////////////////////////////////////////////////////
 // SystemModalContainerLayoutManager, public:
 
@@ -188,7 +161,11 @@ void SystemModalContainerLayoutManager::CreateModalBackground() {
     modal_background_->Init(params);
     modal_background_->GetNativeView()->SetName(
         "SystemModalContainerLayoutManager.ModalBackground");
-    modal_background_->SetContentsView(new ModalBackgroundView);
+    views::View* contents_view = new views::View();
+    contents_view->set_background(views::Background::CreateSolidBackground(
+        CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kEnableNewDialogStyle) ? SK_ColorWHITE : SK_ColorBLACK));
+    modal_background_->SetContentsView(contents_view);
     modal_background_->GetNativeView()->layer()->SetOpacity(0.0f);
   }