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

chrome/browser/ui/metro_pin_tab_helper.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/metro_pin_tab_helper.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/ui/metro_pinned_state_observer.h"
 #include "content/public/browser/web_contents.h"
 
 #if defined(OS_WIN)
 #include "base/win/metro.h"
 #endif
 
 MetroPinTabHelper::MetroPinTabHelper(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
-      is_pinned_(false) {}
+      is_pinned_(false),
+      observer_(NULL) {}
 
 MetroPinTabHelper::~MetroPinTabHelper() {}
 
 void MetroPinTabHelper::TogglePinnedToStartScreen() {
 #if defined(OS_WIN)
   HMODULE metro_module = base::win::GetMetroModule();
   if (metro_module) {
     typedef void (*MetroTogglePinnedToStartScreen)(const string16&,
         const string16&);
     MetroTogglePinnedToStartScreen metro_toggle_pinned_to_start_screen =
         reinterpret_cast<MetroTogglePinnedToStartScreen>(
             ::GetProcAddress(metro_module, "MetroTogglePinnedToStartScreen"));
     if (!metro_toggle_pinned_to_start_screen) {
       NOTREACHED();
       return;
     }
 
     GURL url = web_contents()->GetURL();
     string16 title = web_contents()->GetTitle();
     VLOG(1) << __FUNCTION__ << " calling pin with title: " << title
             << " and url " << UTF8ToUTF16(url.spec());
     metro_toggle_pinned_to_start_screen(title, UTF8ToUTF16(url.spec()));
     // TODO(benwells): This will update the state incorrectly if the user
     // cancels. To fix this some sort of callback needs to be introduced as
     // the pinning happens on another thread.
-    is_pinned_ = !is_pinned_;
-    return;
+    SetIsPinned(!is_pinned_);
   }
 #endif
 }
 
 void MetroPinTabHelper::DidNavigateMainFrame(
     const content::LoadCommittedDetails& /*details*/,
     const content::FrameNavigateParams& /*params*/) {
   UpdatePinnedStateForCurrentURL();
 }
 
 void MetroPinTabHelper::UpdatePinnedStateForCurrentURL() {
 #if defined(OS_WIN)
   HMODULE metro_module = base::win::GetMetroModule();
   if (metro_module) {
     typedef BOOL (*MetroIsPinnedToStartScreen)(const string16&);
     MetroIsPinnedToStartScreen metro_is_pinned_to_start_screen =
         reinterpret_cast<MetroIsPinnedToStartScreen>(
             ::GetProcAddress(metro_module, "MetroIsPinnedToStartScreen"));
     if (!metro_is_pinned_to_start_screen) {
       NOTREACHED();
       return;
     }
 
     GURL url = web_contents()->GetURL();
-    is_pinned_ = metro_is_pinned_to_start_screen(UTF8ToUTF16(url.spec())) != 0;
+    SetIsPinned(metro_is_pinned_to_start_screen(UTF8ToUTF16(url.spec())) != 0);
     VLOG(1) << __FUNCTION__ << " with url " << UTF8ToUTF16(url.spec())
             << " result: " << is_pinned_;
   }
 #endif
 }
+
+void MetroPinTabHelper::SetIsPinned(bool is_pinned) {
+  bool was_pinned = is_pinned_;
+  is_pinned_ = is_pinned;
+  if (observer_ && is_pinned_ != was_pinned)
+    observer_->MetroPinnedStateChanged(web_contents(), is_pinned_);
+}