Add pin icon to the omnibar in windows 8 metro mode.

chrome/browser/ui/metro_pin_tab_helper.h

Index: chrome/browser/ui/metro_pin_tab_helper.h
diff --git a/chrome/browser/ui/metro_pin_tab_helper.h b/chrome/browser/ui/metro_pin_tab_helper.h
index c72e503236209ea9eb48a5f37c71b16d2b93737e..f4732d2ad16cd570752886f485f2bd5243b96416 100644
--- a/chrome/browser/ui/metro_pin_tab_helper.h
+++ b/chrome/browser/ui/metro_pin_tab_helper.h
@@ -7,14 +7,20 @@
 
 #include "content/public/browser/web_contents_observer.h"
 
+class MetroPinnedStateObserver;
+
 // Per-tab class to help manage metro pinning.
 class MetroPinTabHelper : public content::WebContentsObserver {
  public:
-  explicit MetroPinTabHelper(content::WebContents* tab_contents);
+  explicit MetroPinTabHelper(content::WebContents* web_contents);
   virtual ~MetroPinTabHelper();
 
   bool is_pinned() const { return is_pinned_; }
 
+  void set_observer(MetroPinnedStateObserver* observer) {
+    observer_ = observer;
+  }
+
   void TogglePinnedToStartScreen();
 
   // content::WebContentsObserver overrides:
@@ -26,9 +32,15 @@ class MetroPinTabHelper : public content::WebContentsObserver {
   // Queries the metro driver about the pinned state of the current URL.
   void UpdatePinnedStateForCurrentURL();
 
+  // Update the pinned state and notify the delegate.
+  void SetIsPinned(bool is_pinned);
+
   // Whether the current URL is pinned to the metro start screen.
   bool is_pinned_;
 
+  // The observer that we inform when the |is_pinned_| state changes.
+  MetroPinnedStateObserver* observer_;
+
   DISALLOW_COPY_AND_ASSIGN(MetroPinTabHelper);
 };