GTK Themes: Prevent colors from "leaking through" by using an event box.

chrome/browser/gtk/browser_toolbar_gtk.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_GTK_BROWSER_TOOLBAR_GTK_H_
 #define CHROME_BROWSER_GTK_BROWSER_TOOLBAR_GTK_H_
 
 #include <gtk/gtk.h>
 #include <string>
 
@@ skipping 31 matching lines @@
   void Init(Profile* profile, GtkWindow* top_level_window);
 
   // Adds this GTK toolbar into a sizing box.
   void AddToolbarToBox(GtkWidget* box);
 
   void Show();
   void Hide();
 
   // Getter for the containing widget.
   GtkWidget* widget() {
-    return toolbar_;
+    return event_box_;
   }
 
   virtual LocationBar* GetLocationBar() const;
 
   GoButtonGtk* GetGoButton() { return go_.get(); }
 
   // Overridden from CommandUpdater::CommandObserver:
   virtual void EnabledStateChangedForCommand(int id, bool enabled);
 
   // Overridden from MenuGtk::Delegate:
@@ skipping 82 matching lines @@
   static void OnPageAppMenuMoveCurrent(GtkWidget* widget,
                                        GtkMenuDirectionType dir,
                                        BrowserToolbarGtk* toolbar);
 
   // Initialize the background NineBox.
   void InitNineBox();
 
   // Ninebox for the toolbar background
   scoped_ptr<NineBox> background_ninebox_;
 
+  // An event box that holds |toolbar_|. We need the toolbar to have its own
+  // GdkWindow when we use the GTK drawing because otherwise the color from our
+  // parent GdkWindow will leak through with some theme engines (such as
+  // Clearlooks).
+  GtkWidget* event_box_;
+
   // Gtk widgets. The toolbar is an hbox with each of the other pieces of the
   // toolbar placed side by side.
   GtkWidget* toolbar_;
 
   // The location bar view.
   scoped_ptr<LocationBarViewGtk> location_bar_;
 
   // A pointer to our window's accelerator list.
   GtkAccelGroup* accel_group_;
 
@@ skipping 18 matching lines @@
   // Controls whether or not a home button should be shown on the toolbar.
   BooleanPrefMember show_home_button_;
 
   // The event state the last time we observed a button release event.
   int last_release_event_flags_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserToolbarGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_BROWSER_TOOLBAR_GTK_H_