GTK: Use IDR_THEME_WINDOW_CONTROL_BACKGROUND when drawing min/max/close and new tab buttons.

chrome/browser/ui/gtk/tabs/tab_strip_gtk.h

Index: chrome/browser/ui/gtk/tabs/tab_strip_gtk.h
diff --git a/chrome/browser/ui/gtk/tabs/tab_strip_gtk.h b/chrome/browser/ui/gtk/tabs/tab_strip_gtk.h
index e104d2e5f10b61617270138e5e7ed9c274553cb7..8669955172026da6e7146f614c1a0fe76743a13d 100644
--- a/chrome/browser/ui/gtk/tabs/tab_strip_gtk.h
+++ b/chrome/browser/ui/gtk/tabs/tab_strip_gtk.h
@@ -18,6 +18,8 @@
 #include "chrome/browser/ui/gtk/tabstrip_origin_provider.h"
 #include "chrome/browser/ui/gtk/view_id_util.h"
 #include "chrome/browser/ui/tabs/hover_tab_selector.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
 #include "ui/base/gtk/gtk_signal.h"
 #include "ui/base/gtk/owned_widget_gtk.h"
 #include "ui/gfx/rect.h"
@@ -30,6 +32,7 @@ class GtkThemeService;
 class TabStripGtk : public TabStripModelObserver,
                     public TabGtk::TabDelegate,
                     public MessageLoopForUI::Observer,
+                    public content::NotificationObserver,
                     public TabstripOriginProvider,
                     public ViewIDUtil::Delegate {
  public:
@@ -151,8 +154,13 @@ class TabStripGtk : public TabStripModelObserver,
   virtual TabStripMenuController* GetTabStripMenuControllerForTab(TabGtk* tab);
 
   // MessageLoop::Observer implementation:
-  virtual void WillProcessEvent(GdkEvent* event);
-  virtual void DidProcessEvent(GdkEvent* event);
+  virtual void WillProcessEvent(GdkEvent* event) OVERRIDE;
+  virtual void DidProcessEvent(GdkEvent* event) OVERRIDE;
+
+  // Overridden from content::NotificationObserver:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
 
   // Horizontal gap between mini-tabs and normal tabs.
   static const int mini_to_non_mini_gap_;
@@ -277,6 +285,9 @@ class TabStripGtk : public TabStripModelObserver,
   // Initializes the new tab button.
   CustomDrawButton* MakeNewTabButton();
 
+  // Sets the theme specific background on the new tab button.
+  void SetNewTabButtonBackground();
+
   // Gets the number of Tabs in the collection.
   int GetTabCount() const;
 
@@ -478,6 +489,8 @@ class TabStripGtk : public TabStripModelObserver,
   // Helper for performing tab selection as a result of dragging over a tab.
   HoverTabSelector hover_tab_selector_;
 
+  content::NotificationRegistrar registrar_;
+
   DISALLOW_COPY_AND_ASSIGN(TabStripGtk);
 };