[gtk] tabcontents fade-out for instant.

chrome/browser/renderer_host/render_widget_host_view_gtk.h

Index: chrome/browser/renderer_host/render_widget_host_view_gtk.h
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.h b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
index 06655588d095ed64ccf402d7b68cab4e3c06372a..cd89ddbc6a654a868d68dd850a46321ca79a4f9c 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.h
@@ -11,6 +11,8 @@
 #include <vector>
 #include <string>
 
+#include "app/animation_delegate.h"
+#include "app/slide_animation.h"
 #include "base/scoped_ptr.h"
 #include "base/time.h"
 #include "chrome/browser/gtk/owned_widget_gtk.h"
@@ -40,7 +42,8 @@ typedef struct _GtkSelectionData GtkSelectionData;
 // -----------------------------------------------------------------------------
 // See comments in render_widget_host_view.h about this class and its members.
 // -----------------------------------------------------------------------------
-class RenderWidgetHostViewGtk : public RenderWidgetHostView {
+class RenderWidgetHostViewGtk : public RenderWidgetHostView,
+                                public AnimationDelegate {
  public:
   explicit RenderWidgetHostViewGtk(RenderWidgetHost* widget);
   ~RenderWidgetHostViewGtk();
@@ -84,10 +87,15 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView {
   virtual void SetBackground(const SkBitmap& background);
   virtual void CreatePluginContainer(gfx::PluginWindowHandle id);
   virtual void DestroyPluginContainer(gfx::PluginWindowHandle id);
-  virtual void SetVisuallyDeemphasized(bool deemphasized);
+  virtual void SetVisuallyDeemphasized(const SkColor* color, bool animate);
   virtual bool ContainsNativeView(gfx::NativeView native_view) const;
   virtual void AcceleratedCompositingActivated(bool activated);
 
+  // AnimationDelegate implementation.
+  virtual void AnimationEnded(const Animation* animation);
+  virtual void AnimationProgressed(const Animation* animation);
+  virtual void AnimationCanceled(const Animation* animation);
+
   gfx::NativeView native_view() const { return view_.get(); }
 
   // If the widget is aligned with an edge of the monitor its on and the user
@@ -164,8 +172,13 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView {
   // The time it took after this view was selected for it to be fully painted.
   base::TimeTicks tab_switch_paint_time_;
 
-  // If true, fade the render widget when painting it.
-  bool visually_deemphasized_;
+  // A color we use to shade the entire render view. If 100% transparent, we do
+  // not shade the render view.
+  SkColor overlay_color_;
+
+  // The animation used for the abovementioned shade effect. The animation's
+  // value affects the alpha we use for |overlay_color_|.
+  SlideAnimation overlay_animation_;
 
   // Variables used only for popups --------------------------------------------
   // Our parent widget.