Get rid of extensions dependency from content\browser.

BUG=76789
Review URL: http://codereview.chromium.org/6693054

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80315 0039d316-1c4b-4281-b951-d872f2087c98

55 files changed, 465 insertions, 274 deletions

diff --git a/chrome/browser/browser_browsertest.cc b/chrome/browser/browser_browsertest.cc
index eef69ef..4b1c38c 100644
--- a/chrome/browser/browser_browsertest.cc
+++ b/chrome/browser/browser_browsertest.cc
@@ -12,6 +12,7 @@
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tabs/pinned_tab_codec.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
@@ -490,7 +491,7 @@ IN_PROC_BROWSER_TEST_F(BrowserTest, TabClosingWhenRemovingExtension) {
   TabContentsWrapper* app_contents =
       Browser::TabContentsFactory(browser()->profile(), NULL,
                                   MSG_ROUTING_NONE, NULL, NULL);
-  app_contents->tab_contents()->SetExtensionApp(extension_app);
+  app_contents->extension_tab_helper()->SetExtensionApp(extension_app);
 
   model->AddTabContents(app_contents, 0, 0, TabStripModel::ADD_NONE);
   model->SetTabPinned(0, true);
@@ -611,7 +612,7 @@ IN_PROC_BROWSER_TEST_F(BrowserTest, RestorePinnedTabs) {
   TabContentsWrapper* app_contents =
     Browser::TabContentsFactory(browser()->profile(), NULL,
                                 MSG_ROUTING_NONE, NULL, NULL);
-  app_contents->tab_contents()->SetExtensionApp(extension_app);
+  app_contents->extension_tab_helper()->SetExtensionApp(extension_app);
   model->AddTabContents(app_contents, 0, 0, TabStripModel::ADD_NONE);
   model->SetTabPinned(0, true);
   ui_test_utils::NavigateToURL(browser(), url);
@@ -664,7 +665,7 @@ IN_PROC_BROWSER_TEST_F(BrowserTest, RestorePinnedTabs) {
       new_model->GetTabContentsAt(2)->tab_contents()->GetURL());
 
   EXPECT_TRUE(
-      new_model->GetTabContentsAt(0)->tab_contents()->extension_app() ==
+      new_model->GetTabContentsAt(0)->extension_tab_helper()->extension_app() ==
           extension_app);
 }
 #endif  // !defined(OS_CHROMEOS)
@@ -696,7 +697,9 @@ IN_PROC_BROWSER_TEST_F(BrowserTest, OpenAppWindowLikeNtp) {
 
   // Apps launched in a window from the NTP do not have extension_app set in
   // tab contents.
-  EXPECT_FALSE(app_window->extension_app());
+  TabContentsWrapper* wrapper =
+          TabContentsWrapper::GetCurrentWrapperForContents(app_window);
+  EXPECT_FALSE(wrapper->extension_tab_helper()->extension_app());
   EXPECT_EQ(extension_app->GetFullLaunchURL(), app_window->GetURL());
 
   // The launch should have created a new browser.
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 58a63a5..00ac1c9 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -32,4 +32,23 @@ content::WebUIFactory* ChromeContentBrowserClient::GetWebUIFactory() {
   return ChromeWebUIFactory::GetInstance();
 }
 
+GURL ChromeContentBrowserClient::GetEffectiveURL(Profile* profile,
+                                                 const GURL& url) {
+  // Get the effective URL for the given actual URL. If the URL is part of an
+  // installed app, the effective URL is an extension URL with the ID of that
+  // extension as the host. This has the effect of grouping apps together in
+  // a common SiteInstance.
+  if (!profile || !profile->GetExtensionService())
+    return url;
+
+  const Extension* extension =
+      profile->GetExtensionService()->GetExtensionByWebExtent(url);
+  if (!extension)
+    return url;
+
+  // If the URL is part of an extension's web extent, convert it to an
+  // extension URL.
+  return extension->GetResourceURL(url.path());
+}
+
 }  // namespace chrome
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index dd71656..c55fbae 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -16,6 +16,7 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
                                    Profile* profile,
                                    const GURL& url);
   virtual content::WebUIFactory* GetWebUIFactory();
+  virtual GURL GetEffectiveURL(Profile* profile, const GURL& url);
 };
 
 }  // namespace chrome
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 1b05b26..a663fdb 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -32,6 +32,7 @@
 #include "chrome/common/bindings_policy.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_constants.h"
+#include "chrome/common/extensions/extension_messages.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/common/view_types.h"
@@ -793,6 +794,7 @@ bool ExtensionHost::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ExtensionHost, message)
     IPC_MESSAGE_HANDLER(ViewHostMsg_RunFileChooser, OnRunFileChooser)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_PostMessage, OnPostMessage)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -849,3 +851,10 @@ void ExtensionHost::OnRunFileChooser(
     file_select_helper_.reset(new FileSelectHelper(profile()));
   file_select_helper_->RunFileChooser(render_view_host_, params);
 }
+
+void ExtensionHost::OnPostMessage(int port_id, const std::string& message) {
+  if (profile()->GetExtensionMessageService()) {
+    profile()->GetExtensionMessageService()->PostMessageFromRenderer(
+        port_id, message);
+  }
+}
diff --git a/chrome/browser/extensions/extension_host.h b/chrome/browser/extensions/extension_host.h
index e08885c..1601a8c 100644
--- a/chrome/browser/extensions/extension_host.h
+++ b/chrome/browser/extensions/extension_host.h
@@ -232,6 +232,7 @@ class ExtensionHost : public RenderViewHostDelegate,
 
   // Message handlers.
   void OnRunFileChooser(const ViewHostMsg_RunFileChooser_Params& params);
+  void OnPostMessage(int port_id, const std::string& message);
 
   // Handles keyboard events that were not handled by HandleKeyboardEvent().
   // Platform specific implementation may override this method to handle the
diff --git a/chrome/browser/extensions/extension_page_actions_module.cc b/chrome/browser/extensions/extension_page_actions_module.cc
index 2750c18..efdad78 100644
--- a/chrome/browser/extensions/extension_page_actions_module.cc
+++ b/chrome/browser/extensions/extension_page_actions_module.cc
@@ -9,6 +9,7 @@
 #include "base/string_number_conversions.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/extensions/extension_page_actions_module_constants.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ -89,7 +90,7 @@ bool PageActionFunction::SetPageActionEnabled(bool enable) {
   page_action->SetIsVisible(tab_id, enable);
   page_action->SetTitle(tab_id, title);
   page_action->SetIconIndex(tab_id, icon_id);
-  contents->tab_contents()->PageActionStateChanged();
+  contents->extension_tab_helper()->PageActionStateChanged();
 
   return true;
 }
@@ -111,7 +112,7 @@ bool PageActionFunction::InitCommon(int tab_id) {
         kNoTabError, base::IntToString(tab_id));
     return false;
   }
-  contents_ = wrapper->tab_contents();
+  contents_ = wrapper;
 
   return true;
 }
@@ -123,7 +124,7 @@ bool PageActionFunction::SetVisible(bool visible) {
     return false;
 
   page_action_->SetIsVisible(tab_id, visible);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -175,7 +176,7 @@ bool PageActionSetIconFunction::RunImpl() {
     EXTENSION_FUNCTION_VALIDATE(false);
   }
 
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -192,7 +193,7 @@ bool PageActionSetTitleFunction::RunImpl() {
   EXTENSION_FUNCTION_VALIDATE(args->GetString("title", &title));
 
   page_action_->SetTitle(tab_id, title);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -215,7 +216,7 @@ bool PageActionSetPopupFunction::RunImpl() {
     popup_url = GetExtension()->GetResourceURL(popup_string);
 
   page_action_->SetPopupUrl(tab_id, popup_url);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -241,7 +242,7 @@ bool PageActionSetBadgeBackgroundColorFunction::RunImpl() {
   SkColor color = SkColorSetARGB(color_array[3], color_array[0], color_array[1],
                                  color_array[2]);
   page_action_->SetBadgeBackgroundColor(tab_id, color);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -267,7 +268,7 @@ bool PageActionSetBadgeTextColorFunction::RunImpl() {
   SkColor color = SkColorSetARGB(color_array[3], color_array[0], color_array[1],
                                  color_array[2]);
   page_action_->SetBadgeTextColor(tab_id, color);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
 
@@ -286,6 +287,6 @@ bool PageActionSetBadgeTextFunction::RunImpl() {
   EXTENSION_FUNCTION_VALIDATE(args->GetString("text", &text));
 
   page_action_->SetBadgeText(tab_id, text);
-  contents_->PageActionStateChanged();
+  contents_->extension_tab_helper()->PageActionStateChanged();
   return true;
 }
diff --git a/chrome/browser/extensions/extension_page_actions_module.h b/chrome/browser/extensions/extension_page_actions_module.h
index dfbda0a..ee99906 100644
--- a/chrome/browser/extensions/extension_page_actions_module.h
+++ b/chrome/browser/extensions/extension_page_actions_module.h
@@ -8,7 +8,7 @@
 
 #include "chrome/browser/extensions/extension_function.h"
 
-class TabContents;
+class TabContentsWrapper;
 class ExtensionAction;
 
 // Base class for page action APIs.
@@ -21,7 +21,7 @@ class PageActionFunction : public SyncExtensionFunction {
   bool SetVisible(bool visible);
 
   ExtensionAction* page_action_;
-  TabContents* contents_;
+  TabContentsWrapper* contents_;
 };
 
 // Implement chrome.pageActions.enableForTab().
diff --git a/chrome/browser/extensions/extension_startup_browsertest.cc b/chrome/browser/extensions/extension_startup_browsertest.cc
index 129e184..e139365 100644
--- a/chrome/browser/extensions/extension_startup_browsertest.cc
+++ b/chrome/browser/extensions/extension_startup_browsertest.cc
@@ -78,6 +78,8 @@ class ExtensionStartupTestBase : public InProcessBrowserTest {
     // TODO(phajdan.jr): Check return values of the functions below, carefully.
     file_util::Delete(user_scripts_dir_, true);
     file_util::Delete(extensions_dir_, true);
+
+    InProcessBrowserTest::TearDown();
   }
 
   void WaitForServicesToStart(int num_expected_extensions,
diff --git a/chrome/browser/extensions/extension_tab_helper.cc b/chrome/browser/extensions/extension_tab_helper.cc
new file mode 100644
index 0000000..16c3534
--- /dev/null
+++ b/chrome/browser/extensions/extension_tab_helper.cc
@@ -0,0 +1,144 @@
+// Copyright (c) 2011 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/extensions/extension_tab_helper.h"
+
+#include "chrome/browser/extensions/extension_message_service.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/extension_action.h"
+#include "chrome/common/extensions/extension_icon_set.h"
+#include "chrome/common/extensions/extension_messages.h"
+#include "chrome/common/extensions/extension_resource.h"
+#include "content/browser/tab_contents/tab_contents.h"
+#include "content/browser/tab_contents/navigation_controller.h"
+#include "content/common/notification_service.h"
+
+ExtensionTabHelper::ExtensionTabHelper(TabContents* tab_contents)
+    : TabContentsObserver(tab_contents),
+      extension_app_(NULL) {
+}
+
+ExtensionTabHelper::~ExtensionTabHelper() {
+}
+
+void ExtensionTabHelper::CopyStateFrom(const ExtensionTabHelper& source) {
+  SetExtensionApp(source.extension_app());
+  extension_app_icon_ = source.extension_app_icon_;
+}
+
+void ExtensionTabHelper::PageActionStateChanged() {
+  tab_contents()->NotifyNavigationStateChanged(
+      TabContents::INVALIDATE_PAGE_ACTIONS);
+}
+
+void ExtensionTabHelper::SetExtensionApp(const Extension* extension) {
+  DCHECK(!extension || extension->GetFullLaunchURL().is_valid());
+  extension_app_ = extension;
+
+  UpdateExtensionAppIcon(extension_app_);
+
+  NotificationService::current()->Notify(
+      NotificationType::TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED,
+      Source<ExtensionTabHelper>(this),
+      NotificationService::NoDetails());
+}
+
+void ExtensionTabHelper::SetExtensionAppById(
+    const std::string& extension_app_id) {
+  if (extension_app_id.empty())
+    return;
+
+  ExtensionService* extension_service =
+      tab_contents()->profile()->GetExtensionService();
+  if (!extension_service || !extension_service->is_ready())
+    return;
+
+  const Extension* extension =
+      extension_service->GetExtensionById(extension_app_id, false);
+  if (extension)
+    SetExtensionApp(extension);
+}
+
+SkBitmap* ExtensionTabHelper::GetExtensionAppIcon() {
+  if (extension_app_icon_.empty())
+    return NULL;
+
+  return &extension_app_icon_;
+}
+
+void ExtensionTabHelper::DidNavigateMainFramePostCommit(
+    const NavigationController::LoadCommittedDetails& details,
+    const ViewHostMsg_FrameNavigate_Params& params) {
+  if (details.is_in_page)
+    return;
+
+  ExtensionService* service = tab_contents()->profile()->GetExtensionService();
+  if (!service)
+    return;
+
+  for (size_t i = 0; i < service->extensions()->size(); ++i) {
+    ExtensionAction* browser_action =
+        service->extensions()->at(i)->browser_action();
+    if (browser_action) {
+      browser_action->ClearAllValuesForTab(
+          tab_contents()->controller().session_id().id());
+      NotificationService::current()->Notify(
+          NotificationType::EXTENSION_BROWSER_ACTION_UPDATED,
+          Source<ExtensionAction>(browser_action),
+          NotificationService::NoDetails());
+    }
+
+    ExtensionAction* page_action =
+        service->extensions()->at(i)->page_action();
+    if (page_action) {
+      page_action->ClearAllValuesForTab(
+          tab_contents()->controller().session_id().id());
+      PageActionStateChanged();
+    }
+  }
+}
+
+bool ExtensionTabHelper::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ExtensionTabHelper, message)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_PostMessage, OnPostMessage)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void ExtensionTabHelper::UpdateExtensionAppIcon(const Extension* extension) {
+  extension_app_icon_.reset();
+
+  if (extension) {
+    extension_app_image_loader_.reset(new ImageLoadingTracker(this));
+    extension_app_image_loader_->LoadImage(
+        extension,
+        extension->GetIconResource(Extension::EXTENSION_ICON_SMALLISH,
+                                   ExtensionIconSet::MATCH_EXACTLY),
+        gfx::Size(Extension::EXTENSION_ICON_SMALLISH,
+                  Extension::EXTENSION_ICON_SMALLISH),
+        ImageLoadingTracker::CACHE);
+  } else {
+    extension_app_image_loader_.reset(NULL);
+  }
+}
+
+void ExtensionTabHelper::OnImageLoaded(SkBitmap* image,
+                                       const ExtensionResource& resource,
+                                       int index) {
+  if (image) {
+    extension_app_icon_ = *image;
+    tab_contents()->NotifyNavigationStateChanged(TabContents::INVALIDATE_TAB);
+  }
+}
+
+void ExtensionTabHelper::OnPostMessage(int port_id,
+                                       const std::string& message) {
+  if (tab_contents()->profile()->GetExtensionMessageService()) {
+    tab_contents()->profile()->GetExtensionMessageService()->
+        PostMessageFromRenderer(port_id, message);
+  }
+}
diff --git a/chrome/browser/extensions/extension_tab_helper.h b/chrome/browser/extensions/extension_tab_helper.h
new file mode 100644
index 0000000..5b9c60a
--- /dev/null
+++ b/chrome/browser/extensions/extension_tab_helper.h
@@ -0,0 +1,93 @@
+// Copyright (c) 2011 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_EXTENSIONS_EXTENSOIN_TAB_HELPER_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSOIN_TAB_HELPER_H_
+#pragma once
+
+#include "content/browser/tab_contents/tab_contents_observer.h"
+#include "chrome/browser/extensions/image_loading_tracker.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+class Extension;
+
+// Per-tab extension helper.
+class ExtensionTabHelper : public TabContentsObserver,
+                           public ImageLoadingTracker::Observer {
+ public:
+  explicit ExtensionTabHelper(TabContents* tab_contents);
+  virtual ~ExtensionTabHelper();
+
+  // Copies the internal state from another ExtensionTabHelper.
+  void CopyStateFrom(const ExtensionTabHelper& source);
+
+  // Call this after updating a page action to notify clients about the changes.
+  void PageActionStateChanged();
+
+  // App extensions ------------------------------------------------------------
+
+  // Sets the extension denoting this as an app. If |extension| is non-null this
+  // tab becomes an app-tab. TabContents does not listen for unload events for
+  // the extension. It's up to consumers of TabContents to do that.
+  //
+  // NOTE: this should only be manipulated before the tab is added to a browser.
+  // TODO(sky): resolve if this is the right way to identify an app tab. If it
+  // is, than this should be passed in the constructor.
+  void SetExtensionApp(const Extension* extension);
+
+  // Convenience for setting the app extension by id. This does nothing if
+  // |extension_app_id| is empty, or an extension can't be found given the
+  // specified id.
+  void SetExtensionAppById(const std::string& extension_app_id);
+
+  const Extension* extension_app() const { return extension_app_; }
+  bool is_app() const { return extension_app_ != NULL; }
+
+  // If an app extension has been explicitly set for this TabContents its icon
+  // is returned.
+  //
+  // NOTE: the returned icon is larger than 16x16 (its size is
+  // Extension::EXTENSION_ICON_SMALLISH).
+  SkBitmap* GetExtensionAppIcon();
+
+  TabContents* tab_contents() const {
+      return TabContentsObserver::tab_contents();
+  }
+
+ private:
+  // TabContentsObserver overrides.
+  virtual void DidNavigateMainFramePostCommit(
+      const NavigationController::LoadCommittedDetails& details,
+      const ViewHostMsg_FrameNavigate_Params& params) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  // App extensions related methods:
+
+  // Resets app_icon_ and if |extension| is non-null creates a new
+  // ImageLoadingTracker to load the extension's image.
+  void UpdateExtensionAppIcon(const Extension* extension);
+
+  // ImageLoadingTracker::Observer.
+  virtual void OnImageLoaded(SkBitmap* image, const ExtensionResource& resource,
+                             int index);
+
+  // Message handlers.
+  void OnPostMessage(int port_id, const std::string& message);
+
+  // Data for app extensions ---------------------------------------------------
+
+  // If non-null this tab is an app tab and this is the extension the tab was
+  // created for.
+  const Extension* extension_app_;
+
+  // Icon for extension_app_ (if non-null) or extension_for_current_page_.
+  SkBitmap extension_app_icon_;
+
+  // Used for loading extension_app_icon_.
+  scoped_ptr<ImageLoadingTracker> extension_app_image_loader_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTabHelper);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSOIN_TAB_HELPER_H_
diff --git a/chrome/browser/sessions/session_service.cc b/chrome/browser/sessions/session_service.cc
index 2431086..fa9ecae 100644
--- a/chrome/browser/sessions/session_service.cc
+++ b/chrome/browser/sessions/session_service.cc
@@ -17,6 +17,7 @@
 #include "base/threading/thread.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/browser_window.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/prefs/session_startup_pref.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_backend.h"
@@ -25,6 +26,7 @@
 #include "chrome/browser/sessions/session_types.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/browser_init.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/browser/tab_contents/navigation_controller.h"
 #include "content/browser/tab_contents/navigation_entry.h"
@@ -518,11 +520,14 @@ void SessionService::Observe(NotificationType type,
       NavigationController* controller =
           Source<NavigationController>(source).ptr();
       SetTabWindow(controller->window_id(), controller->session_id());
-      if (controller->tab_contents()->extension_app()) {
+      TabContentsWrapper* wrapper =
+          TabContentsWrapper::GetCurrentWrapperForContents(
+              controller->tab_contents());
+      if (wrapper->extension_tab_helper()->extension_app()) {
         SetTabExtensionAppID(
             controller->window_id(),
             controller->session_id(),
-            controller->tab_contents()->extension_app()->id());
+            wrapper->extension_tab_helper()->extension_app()->id());
       }
       break;
     }
@@ -584,12 +589,13 @@ void SessionService::Observe(NotificationType type,
     }
 
     case NotificationType::TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED: {
-      TabContents* tab_contents = Source<TabContents>(source).ptr();
-      DCHECK(tab_contents);
-      if (tab_contents->extension_app()) {
-        SetTabExtensionAppID(tab_contents->controller().window_id(),
-                             tab_contents->controller().session_id(),
-                             tab_contents->extension_app()->id());
+      ExtensionTabHelper* extension_tab_helper =
+          Source<ExtensionTabHelper>(source).ptr();
+      if (extension_tab_helper->extension_app()) {
+        SetTabExtensionAppID(
+            extension_tab_helper->tab_contents()->controller().window_id(),
+            extension_tab_helper->tab_contents()->controller().session_id(),
+            extension_tab_helper->extension_app()->id());
       }
       break;
     }
@@ -1072,12 +1078,15 @@ void SessionService::BuildCommandsForTab(
     commands->push_back(
         CreatePinnedStateCommand(controller->session_id(), true));
   }
-  if (controller->tab_contents()->extension_app()) {
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(
+          controller->tab_contents());
+  if (wrapper->extension_tab_helper()->extension_app()) {
     commands->push_back(
         CreateSetTabExtensionAppIDCommand(
             kCommandSetExtensionAppID,
             controller->session_id().id(),
-            controller->tab_contents()->extension_app()->id()));
+            wrapper->extension_tab_helper()->extension_app()->id()));
   }
   for (int i = min_index; i < max_index; ++i) {
     const NavigationEntry* entry = (i == pending_index) ?
diff --git a/chrome/browser/sessions/tab_restore_service.cc b/chrome/browser/sessions/tab_restore_service.cc
index b819697..1e81bb1 100644
--- a/chrome/browser/sessions/tab_restore_service.cc
+++ b/chrome/browser/sessions/tab_restore_service.cc
@@ -13,12 +13,14 @@
 #include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_service.h"
 #include "chrome/browser/sessions/session_command.h"
 #include "chrome/browser/sessions/session_types.h"
 #include "chrome/browser/sessions/tab_restore_service_delegate.h"
 #include "chrome/browser/sessions/tab_restore_service_observer.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "content/browser/tab_contents/navigation_controller.h"
@@ -492,9 +494,16 @@ void TabRestoreService::PopulateTab(Tab* tab,
     tab->current_navigation_index = 0;
   tab->tabstrip_index = index;
 
-  const Extension* extension = controller->tab_contents()->extension_app();
-  if (extension)
-    tab->extension_app_id = extension->id();
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(
+          controller->tab_contents());
+  // wrapper is NULL in some browser tests.
+  if (wrapper) {
+    const Extension* extension =
+        wrapper->extension_tab_helper()->extension_app();
+    if (extension)
+      tab->extension_app_id = extension->id();
+  }
 
   tab->session_storage_namespace = controller->session_storage_namespace();
 
diff --git a/chrome/browser/sync/glue/session_change_processor.cc b/chrome/browser/sync/glue/session_change_processor.cc
index d7d33d6..8c8a452 100644
--- a/chrome/browser/sync/glue/session_change_processor.cc
+++ b/chrome/browser/sync/glue/session_change_processor.cc
@@ -10,6 +10,7 @@
 
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/engine/syncapi.h"
 #include "chrome/browser/sync/glue/session_model_associator.h"
@@ -125,13 +126,13 @@ void SessionChangeProcessor::Observe(NotificationType type,
     }
 
     case NotificationType::TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED: {
-      TabContents* tab_contents = Source<TabContents>(source).ptr();
-      DCHECK(tab_contents);
-      if (tab_contents->profile() != profile_) {
+      ExtensionTabHelper* extension_tab_helper =
+          Source<ExtensionTabHelper>(source).ptr();
+      if (extension_tab_helper->tab_contents()->profile() != profile_) {
         return;
       }
-      if (tab_contents->extension_app()) {
-        modified_tabs.push_back(tab_contents);
+      if (extension_tab_helper->extension_app()) {
+        modified_tabs.push_back(extension_tab_helper->tab_contents());
       }
       break;
     }
diff --git a/chrome/browser/sync/glue/session_model_associator.cc b/chrome/browser/sync/glue/session_model_associator.cc
index e02b4a2..28ed7c5 100644
--- a/chrome/browser/sync/glue/session_model_associator.cc
+++ b/chrome/browser/sync/glue/session_model_associator.cc
@@ -10,6 +10,7 @@
 #include "base/logging.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/browser_window.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/syncable/syncable.h"
@@ -18,6 +19,7 @@
 #include "chrome/common/url_constants.h"
 #include "content/browser/tab_contents/navigation_controller.h"
 #include "content/browser/tab_contents/navigation_entry.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "content/common/notification_details.h"
 #include "content/common/notification_service.h"
 
@@ -268,8 +270,13 @@ bool SessionModelAssociator::WriteTabContentsToSyncModel(
   int index_in_window = browser.tabstrip_model()->GetWrapperIndex(&tab);
   DCHECK(index_in_window != TabStripModel::kNoTab);
   tab_s->set_pinned(browser.tabstrip_model()->IsTabPinned(index_in_window));
-  if (tab.extension_app())
-    tab_s->set_extension_app_id(tab.extension_app()->id());
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(
+          const_cast<TabContents*>(&tab));
+  if (wrapper->extension_tab_helper()->extension_app()) {
+    tab_s->set_extension_app_id(
+        wrapper->extension_tab_helper()->extension_app()->id());
+  }
   for (int i = min_index; i < max_index; ++i) {
     const NavigationEntry* entry = (i == pending_index) ?
        tab.controller().pending_entry() : tab.controller().GetEntryAtIndex(i);
diff --git a/chrome/browser/tab_contents/background_contents.cc b/chrome/browser/tab_contents/background_contents.cc
index 933d2da..648aeb2 100644
--- a/chrome/browser/tab_contents/background_contents.cc
+++ b/chrome/browser/tab_contents/background_contents.cc
@@ -6,6 +6,7 @@
 
 #include "chrome/browser/background_contents_service.h"
 #include "chrome/browser/desktop_notification_handler.h"
+#include "chrome/browser/extensions/extension_message_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_preferences_util.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_factory.h"
@@ -197,9 +198,17 @@ void BackgroundContents::RenderViewGone(RenderViewHost* rvh,
 }
 
 bool BackgroundContents::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(BackgroundContents, message)
+    IPC_MESSAGE_HANDLER(ExtensionHostMsg_PostMessage, OnPostMessage)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
   // Forward desktop notification IPCs if any to the
   // DesktopNotificationHandler.
-  return desktop_notification_handler_->OnMessageReceived(message);
+  if (!handled)
+   handled = desktop_notification_handler_->OnMessageReceived(message);
+  return handled;
 }
 
 RendererPreferences BackgroundContents::GetRendererPrefs(
@@ -276,3 +285,12 @@ BackgroundContents::GetBackgroundContentsByID(int render_process_id,
 
   return render_view_host->delegate()->GetAsBackgroundContents();
 }
+
+void BackgroundContents::OnPostMessage(int port_id,
+                                       const std::string& message) {
+  Profile* profile = render_view_host_->process()->profile();
+  if (profile->GetExtensionMessageService()) {
+    profile->GetExtensionMessageService()->PostMessageFromRenderer(
+        port_id, message);
+  }
+}
diff --git a/chrome/browser/tab_contents/background_contents.h b/chrome/browser/tab_contents/background_contents.h
index e8a1847..3db1bfc 100644
--- a/chrome/browser/tab_contents/background_contents.h
+++ b/chrome/browser/tab_contents/background_contents.h
@@ -153,6 +153,9 @@ class BackgroundContents : public RenderViewHostDelegate,
   BackgroundContents();
 
  private:
+  // Message handlers.
+  void OnPostMessage(int port_id, const std::string& message);
+
   // The delegate for this BackgroundContents.
   Delegate* delegate_;
 
diff --git a/chrome/browser/tabs/pinned_tab_codec.cc b/chrome/browser/tabs/pinned_tab_codec.cc
index 7b89949..6680d82 100644
--- a/chrome/browser/tabs/pinned_tab_codec.cc
+++ b/chrome/browser/tabs/pinned_tab_codec.cc
@@ -6,6 +6,7 @@
 
 #include "base/values.h"
 #include "chrome/browser/browser_list.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
@@ -43,7 +44,8 @@ static void EncodePinnedTab(TabStripModel* model,
 
   TabContentsWrapper* tab_contents = model->GetTabContentsAt(index);
   if (model->IsAppTab(index)) {
-    const Extension* extension = tab_contents->extension_app();
+    const Extension* extension =
+        tab_contents->extension_tab_helper()->extension_app();
     DCHECK(extension);
     value->SetString(kAppID, extension->id());
     // For apps we use the launch url. We do this for the following reason:
diff --git a/chrome/browser/tabs/tab_strip_model.cc b/chrome/browser/tabs/tab_strip_model.cc
index 407bb00..7e31c30 100644
--- a/chrome/browser/tabs/tab_strip_model.cc
+++ b/chrome/browser/tabs/tab_strip_model.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
@@ -117,7 +118,8 @@ void TabStripModel::InsertTabContentsAt(int index,
                                         int add_types) {
   bool foreground = add_types & ADD_SELECTED;
   // Force app tabs to be pinned.
-  bool pin = contents->is_app() || add_types & ADD_PINNED;
+  bool pin =
+      contents->extension_tab_helper()->is_app() || add_types & ADD_PINNED;
   index = ConstrainInsertionIndex(index, pin);
 
   // In tab dragging situations, if the last tab in the window was detached
@@ -545,7 +547,7 @@ bool TabStripModel::IsMiniTab(int index) const {
 
 bool TabStripModel::IsAppTab(int index) const {
   TabContentsWrapper* contents = GetTabContentsAt(index);
-  return contents && contents->is_app();
+  return contents && contents->extension_tab_helper()->is_app();
 }
 
 bool TabStripModel::IsTabBlocked(int index) const {
@@ -997,7 +999,7 @@ void TabStripModel::Observe(NotificationType type,
       // Iterate backwards as we may remove items while iterating.
       for (int i = count() - 1; i >= 0; i--) {
         TabContentsWrapper* contents = GetTabContentsAt(i);
-        if (contents->extension_app() == extension) {
+        if (contents->extension_tab_helper()->extension_app() == extension) {
           // The extension an app tab was created from has been nuked. Delete
           // the TabContents. Deleting a TabContents results in a notification
           // of type TAB_CONTENTS_DESTROYED; we do the necessary cleanup in
diff --git a/chrome/browser/tabs/tab_strip_model.h b/chrome/browser/tabs/tab_strip_model.h
index df0c545..42489b4 100644
--- a/chrome/browser/tabs/tab_strip_model.h
+++ b/chrome/browser/tabs/tab_strip_model.h
@@ -41,8 +41,8 @@ class TabStripModelOrderController;
 //   You'll notice there is no explcit api for making a tab a mini-tab, rather
 //   there are two tab types that are implicitly mini-tabs:
 //   . App. Corresponds to an extension that wants an app tab. App tabs are
-//     identified by TabContents::is_app(). App tabs are always pinneded (you
-//     can't unpin them).
+//     identified by TabContentsWrapper::extension_tab_helper()::is_app().
+//     App tabs are always pinneded (you can't unpin them).
 //   . Pinned. Any tab can be pinned. Non-app tabs whose pinned state is changed
 //     are moved to be with other mini-tabs or non-mini tabs.
 //
diff --git a/chrome/browser/tabs/tab_strip_model_unittest.cc b/chrome/browser/tabs/tab_strip_model_unittest.cc
index aac26a9..993f409 100644
--- a/chrome/browser/tabs/tab_strip_model_unittest.cc
+++ b/chrome/browser/tabs/tab_strip_model_unittest.cc
@@ -15,6 +15,7 @@
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
@@ -1759,9 +1760,9 @@ TEST_F(TabStripModelTest, Apps) {
                                                        Extension::INVALID));
   extension_app->launch_web_url_ = "http://www.google.com";
   TabContentsWrapper* contents1 = CreateTabContents();
-  contents1->tab_contents()->SetExtensionApp(extension_app);
+  contents1->extension_tab_helper()->SetExtensionApp(extension_app);
   TabContentsWrapper* contents2 = CreateTabContents();
-  contents2->tab_contents()->SetExtensionApp(extension_app);
+  contents2->extension_tab_helper()->SetExtensionApp(extension_app);
   TabContentsWrapper* contents3 = CreateTabContents();
 
   SetID(contents1->tab_contents(), 1);
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 2289b93..57e3f8b 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -47,6 +47,7 @@
 #include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/extensions/extension_tabs_module.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/google/google_url_tracker.h"
@@ -1054,7 +1055,7 @@ TabContents* Browser::AddRestoredTab(
       GetSelectedTabContents(),
       session_storage_namespace);
   TabContents* new_tab = wrapper->tab_contents();
-  new_tab->SetExtensionAppById(extension_app_id);
+  wrapper->extension_tab_helper()->SetExtensionAppById(extension_app_id);
   new_tab->controller().RestoreFromState(navigations, selected_navigation,
                                          from_last_session);
 
@@ -1096,8 +1097,8 @@ void Browser::ReplaceRestoredTab(
       MSG_ROUTING_NONE,
       GetSelectedTabContents(),
       session_storage_namespace);
+  wrapper->extension_tab_helper()->SetExtensionAppById(extension_app_id);
   TabContents* replacement = wrapper->tab_contents();
-  replacement->SetExtensionAppById(extension_app_id);
   replacement->controller().RestoreFromState(navigations, selected_navigation,
                                              from_last_session);
 
diff --git a/chrome/browser/ui/browser_navigator.cc b/chrome/browser/ui/browser_navigator.cc
index 86754f2..11aca6c 100644
--- a/chrome/browser/ui/browser_navigator.cc
+++ b/chrome/browser/ui/browser_navigator.cc
@@ -10,6 +10,7 @@
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/browser_url_handler.h"
 #include "chrome/browser/browser_window.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/browser.h"
@@ -182,7 +183,8 @@ Browser* GetBrowserForDisposition(browser::NavigateParams* params) {
       // |source| represents an app.
       Browser::Type type = Browser::TYPE_POPUP;
       if ((params->browser && (params->browser->type() & Browser::TYPE_APP)) ||
-          (params->source_contents && params->source_contents->is_app())) {
+          (params->source_contents &&
+           params->source_contents->extension_tab_helper()->is_app())) {
         type = Browser::TYPE_APP_POPUP;
       }
       if (profile) {
@@ -424,7 +426,8 @@ void Navigate(NavigateParams* params) {
       // This function takes ownership of |params->target_contents| until it
       // is added to a TabStripModel.
       target_contents_owner.TakeOwnership();
-      params->target_contents->SetExtensionAppById(params->extension_app_id);
+      params->target_contents->extension_tab_helper()->
+          SetExtensionAppById(params->extension_app_id);
       // TODO(sky): figure out why this is needed. Without it we seem to get
       // failures in startup tests.
       // By default, content believes it is not hidden.  When adding contents
diff --git a/chrome/browser/ui/cocoa/extensions/extension_infobar_controller.mm b/chrome/browser/ui/cocoa/extensions/extension_infobar_controller.mm
index 2b63b2a..982b1d7 100644
--- a/chrome/browser/ui/cocoa/extensions/extension_infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/extensions/extension_infobar_controller.mm
@@ -8,6 +8,7 @@
 
 #include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_infobar_delegate.h"
+#include "chrome/browser/extensions/image_loading_tracker.h"
 #import "chrome/browser/ui/cocoa/animatable_view.h"
 #import "chrome/browser/ui/cocoa/extensions/extension_action_context_menu.h"
 #import "chrome/browser/ui/cocoa/menu_button.h"
diff --git a/chrome/browser/ui/cocoa/tabpose_window.mm b/chrome/browser/ui/cocoa/tabpose_window.mm
index 967767f..4349089 100644
--- a/chrome/browser/ui/cocoa/tabpose_window.mm
+++ b/chrome/browser/ui/cocoa/tabpose_window.mm
@@ -15,6 +15,7 @@
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/browser_process.h"
 #import "chrome/browser/debugger/devtools_window.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
@@ -497,8 +498,8 @@ NSRect Tile::GetFaviconStartRectRelativeTo(const Tile& tile) const {
 }
 
 SkBitmap Tile::favicon() const {
-  if (contents_->is_app()) {
-    SkBitmap* icon = contents_->tab_contents()->GetExtensionAppIcon();
+  if (contents_->extension_tab_helper()->is_app()) {
+    SkBitmap* icon = contents_->extension_tab_helper()->GetExtensionAppIcon();
     if (icon)
       return *icon;
   }
diff --git a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
index b80e6a2..b822232 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm
@@ -17,6 +17,7 @@
 #include "chrome/browser/autocomplete/autocomplete.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ -1327,13 +1328,15 @@ class NotificationBridge : public NotificationObserver {
 // A helper routine for creating an NSImageView to hold the favicon or app icon
 // for |contents|.
 - (NSImageView*)iconImageViewForContents:(TabContents*)contents {
-  BOOL isApp = contents->is_app();
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(contents);
+  BOOL isApp = wrapper->extension_tab_helper()->is_app();
   NSImage* image = nil;
   // Favicons come from the renderer, and the renderer draws everything in the
   // system color space.
   CGColorSpaceRef colorSpace = base::mac::GetSystemColorSpace();
   if (isApp) {
-    SkBitmap* icon = contents->GetExtensionAppIcon();
+    SkBitmap* icon = wrapper->extension_tab_helper()->GetExtensionAppIcon();
     if (icon)
       image = gfx::SkBitmapToNSImageWithColorSpace(*icon, colorSpace);
   } else {
diff --git a/chrome/browser/ui/gtk/tabs/dragged_tab_gtk.cc b/chrome/browser/ui/gtk/tabs/dragged_tab_gtk.cc
index f3ff218..016b091 100644
--- a/chrome/browser/ui/gtk/tabs/dragged_tab_gtk.cc
+++ b/chrome/browser/ui/gtk/tabs/dragged_tab_gtk.cc
@@ -9,12 +9,14 @@
 #include <algorithm>
 
 #include "base/i18n/rtl.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #include "chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "content/browser/renderer_host/backing_store_x.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/tab_contents.h"
@@ -56,8 +58,10 @@ DraggedTabGtk::DraggedTabGtk(TabContents* datasource,
       attached_tab_size_(TabRendererGtk::GetMinimumSelectedSize()),
       contents_size_(contents_size),
       close_animation_(this) {
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(datasource);
   renderer_->UpdateData(datasource,
-                        datasource->is_app(),
+                        wrapper->extension_tab_helper()->is_app(),
                         false); // loading_only
   renderer_->set_mini(mini);
 
diff --git a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
index a57d44b..a3f792a 100644
--- a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
+++ b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.cc
@@ -9,6 +9,7 @@
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/gtk/bookmarks/bookmark_utils_gtk.h"
@@ -292,7 +293,9 @@ void TabRendererGtk::UpdateData(TabContents* contents,
     data_.incognito = contents->profile()->IsOffTheRecord();
     data_.crashed = contents->is_crashed();
 
-    SkBitmap* app_icon = contents->GetExtensionAppIcon();
+    SkBitmap* app_icon =
+        TabContentsWrapper::GetCurrentWrapperForContents(contents)->
+            extension_tab_helper()->GetExtensionAppIcon();
     if (app_icon)
       data_.favicon = *app_icon;
     else
diff --git a/chrome/browser/ui/tab_contents/tab_contents_wrapper.cc b/chrome/browser/ui/tab_contents/tab_contents_wrapper.cc
index 1a27f92..39a0c74 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_wrapper.cc
+++ b/chrome/browser/ui/tab_contents/tab_contents_wrapper.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
 #include "chrome/browser/custom_handlers/register_protocol_handler_infobar_delegate.h"
 #include "chrome/browser/debugger/devtools_handler.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/file_select_helper.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/password_manager/password_manager.h"
@@ -53,6 +54,7 @@ TabContentsWrapper::TabContentsWrapper(TabContents* contents)
   // Create the tab helpers.
   autocomplete_history_manager_.reset(new AutocompleteHistoryManager(contents));
   autofill_manager_.reset(new AutofillManager(contents));
+  extension_tab_helper_.reset(new ExtensionTabHelper(contents));
   find_tab_helper_.reset(new FindTabHelper(contents));
   password_manager_delegate_.reset(new PasswordManagerDelegateImpl(contents));
   password_manager_.reset(
@@ -186,6 +188,9 @@ string16 TabContentsWrapper::GetStatusText() const {
 TabContentsWrapper* TabContentsWrapper::Clone() {
   TabContents* new_contents = tab_contents()->Clone();
   TabContentsWrapper* new_wrapper = new TabContentsWrapper(new_contents);
+
+  new_wrapper->extension_tab_helper()->CopyStateFrom(
+      *extension_tab_helper_.get());
   return new_wrapper;
 }
 
diff --git a/chrome/browser/ui/tab_contents/tab_contents_wrapper.h b/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
index 3a45f87..38ee4f9 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
+++ b/chrome/browser/ui/tab_contents/tab_contents_wrapper.h
@@ -28,6 +28,7 @@ class AutocompleteHistoryManager;
 class AutofillManager;
 class DevToolsObserver;
 class Extension;
+class ExtensionTabHelper;
 class FileSelectObserver;
 class FindTabHelper;
 class NavigationController;
@@ -87,16 +88,6 @@ class TabContentsWrapper : public NotificationObserver,
     return tab_contents()->render_view_host();
   }
   Profile* profile() const { return tab_contents()->profile(); }
-
-  // Convenience methods until extensions are removed from TabContents.
-  void SetExtensionAppById(const std::string& extension_app_id) {
-    tab_contents()->SetExtensionAppById(extension_app_id);
-  }
-  const Extension* extension_app() const {
-    return tab_contents()->extension_app();
-  }
-  bool is_app() const { return tab_contents()->is_app(); }
-
   bool is_starred() const { return is_starred_; }
 
   // Tab Helpers ---------------------------------------------------------------
@@ -107,6 +98,10 @@ class TabContentsWrapper : public NotificationObserver,
 
   AutofillManager* autofill_manager() { return autofill_manager_.get(); }
 
+  ExtensionTabHelper* extension_tab_helper() {
+    return extension_tab_helper_.get();
+  }
+
   FindTabHelper* find_tab_helper() { return find_tab_helper_.get(); }
 
   PasswordManager* password_manager() { return password_manager_.get(); }
@@ -171,6 +166,8 @@ class TabContentsWrapper : public NotificationObserver,
 
   scoped_ptr<AutofillManager> autofill_manager_;
 
+  scoped_ptr<ExtensionTabHelper> extension_tab_helper_;
+
   scoped_ptr<FindTabHelper> find_tab_helper_;
 
   // PasswordManager and its delegate. The delegate must outlive the manager,
diff --git a/chrome/browser/ui/tab_contents/test_tab_contents_wrapper.cc b/chrome/browser/ui/tab_contents/test_tab_contents_wrapper.cc
index 46eac9f..28aa5a4 100644
--- a/chrome/browser/ui/tab_contents/test_tab_contents_wrapper.cc
+++ b/chrome/browser/ui/tab_contents/test_tab_contents_wrapper.cc
@@ -24,7 +24,6 @@ TabContentsWrapper* TabContentsWrapperTestHarness::contents_wrapper() {
 }
 
 void TabContentsWrapperTestHarness::SetUp() {
-  content::GetContentClient()->set_browser(&browser_client_);
   contents_wrapper_.reset(new TabContentsWrapper(CreateTestTabContents()));
 }
 
diff --git a/chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc b/chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc
index 5c976fe..b5ec363 100644
--- a/chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc
+++ b/chrome/browser/ui/views/tabs/browser_tab_strip_controller.cc
@@ -6,6 +6,7 @@
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
@@ -388,11 +389,13 @@ void BrowserTabStripController::SetTabRendererDataFromModel(
     int model_index,
     TabRendererData* data) {
   SkBitmap* app_icon = NULL;
+  TabContentsWrapper* wrapper =
+      TabContentsWrapper::GetCurrentWrapperForContents(contents);
 
   // Extension App icons are slightly larger than favicons, so only allow
   // them if permitted by the model.
   if (model_->delegate()->LargeIconsPermitted())
-    app_icon = contents->GetExtensionAppIcon();
+    app_icon = wrapper->extension_tab_helper()->GetExtensionAppIcon();
 
   if (app_icon)
     data->favicon = *app_icon;
@@ -406,7 +409,7 @@ void BrowserTabStripController::SetTabRendererDataFromModel(
   data->show_icon = contents->ShouldDisplayFavicon();
   data->mini = model_->IsMiniTab(model_index);
   data->blocked = model_->IsTabBlocked(model_index);
-  data->app = contents->is_app();
+  data->app = wrapper->extension_tab_helper()->is_app();
 }
 
 void BrowserTabStripController::StartHighlightTabsForCommand(
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 326d2fd..c9334ec 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -970,6 +970,8 @@
         'browser/extensions/extension_special_storage_policy.h',
         'browser/extensions/extension_tab_id_map.cc',
         'browser/extensions/extension_tab_id_map.h',
+        'browser/extensions/extension_tab_helper.cc',
+        'browser/extensions/extension_tab_helper.h',
         'browser/extensions/extension_tabs_module.cc',
         'browser/extensions/extension_tabs_module.h',
         'browser/extensions/extension_tabs_module_constants.cc',
diff --git a/chrome/test/browser_with_test_window_test.cc b/chrome/test/browser_with_test_window_test.cc
index df70a7e..c945bf0 100644
--- a/chrome/test/browser_with_test_window_test.cc
+++ b/chrome/test/browser_with_test_window_test.cc
@@ -16,7 +16,6 @@
 #include "content/browser/tab_contents/navigation_controller.h"
 #include "content/browser/tab_contents/navigation_entry.h"
 #include "content/browser/tab_contents/tab_contents.h"
-#include "content/common/content_client.h"
 #include "content/common/page_transition_types.h"
 
 BrowserWithTestWindowTest::BrowserWithTestWindowTest()
@@ -33,7 +32,6 @@ void BrowserWithTestWindowTest::SetUp() {
   TestingBrowserProcessTest::SetUp();
 
   profile_.reset(CreateProfile());
-  content::GetContentClient()->set_browser(&browser_client_);
   browser_.reset(new Browser(Browser::TYPE_NORMAL, profile()));
   window_.reset(new TestBrowserWindow(browser()));
   browser_->set_window(window_.get());
diff --git a/chrome/test/browser_with_test_window_test.h b/chrome/test/browser_with_test_window_test.h
index 0cc4711..35be3ad 100644
--- a/chrome/test/browser_with_test_window_test.h
+++ b/chrome/test/browser_with_test_window_test.h
@@ -7,7 +7,6 @@
 #pragma once
 
 #include "base/message_loop.h"
-#include "chrome/browser/chrome_content_browser_client.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/test/test_browser_window.h"
 #include "chrome/test/testing_browser_process_test.h"
@@ -102,7 +101,6 @@ class BrowserWithTestWindowTest : public TestingBrowserProcessTest {
   BrowserThread file_thread_;
 
   scoped_ptr<TestingProfile> profile_;
-  chrome::ChromeContentBrowserClient browser_client_;
   scoped_ptr<TestBrowserWindow> window_;
   scoped_ptr<Browser> browser_;
 
diff --git a/chrome/test/testing_profile.cc b/chrome/test/testing_profile.cc
index 039cbb3..468c051 100644
--- a/chrome/test/testing_profile.cc
+++ b/chrome/test/testing_profile.cc
@@ -796,6 +796,10 @@ PrefService* TestingProfile::GetOffTheRecordPrefs() {
   return NULL;
 }
 
+quota::SpecialStoragePolicy* TestingProfile::GetSpecialStoragePolicy() {
+  return GetExtensionSpecialStoragePolicy();
+}
+
 void TestingProfile::DestroyWebDataService() {
   if (!web_data_service_.get())
     return;
diff --git a/chrome/test/testing_profile.h b/chrome/test/testing_profile.h
index 3ac8d27..154294f 100644
--- a/chrome/test/testing_profile.h
+++ b/chrome/test/testing_profile.h
@@ -20,6 +20,10 @@ namespace net {
 class CookieMonster;
 }
 
+namespace quota {
+class SpecialStoragePolicy;
+}
+
 class AutocompleteClassifier;
 class BookmarkModel;
 class CommandLine;
@@ -283,6 +287,11 @@ class TestingProfile : public Profile {
   virtual prerender::PrerenderManager* GetPrerenderManager();
   virtual PrefService* GetOffTheRecordPrefs();
 
+  // TODO(jam): remove me once webkit_context_unittest.cc doesn't use Profile
+  // and gets the quota::SpecialStoragePolicy* from whatever ends up replacing
+  // it in the content module.
+  quota::SpecialStoragePolicy* GetSpecialStoragePolicy();
+
  protected:
   base::Time start_time_;
   scoped_ptr<PrefService> prefs_;
diff --git a/chrome/test/unit/chrome_test_suite.cc b/chrome/test/unit/chrome_test_suite.cc
index f8eaf48..ea42dce 100644
--- a/chrome/test/unit/chrome_test_suite.cc
+++ b/chrome/test/unit/chrome_test_suite.cc
@@ -99,6 +99,7 @@ void ChromeTestSuite::Initialize() {
 
   // Initialize the content client which that code uses to talk to Chrome.
   content::SetContentClient(&chrome_content_client_);
+  content::GetContentClient()->set_browser(&chrome_browser_content_client_);
 
   chrome::RegisterChromeSchemes();
   host_resolver_proc_ = new LocalHostResolverProc();
diff --git a/chrome/test/unit/chrome_test_suite.h b/chrome/test/unit/chrome_test_suite.h
index be0430c..a8d89e6 100644
--- a/chrome/test/unit/chrome_test_suite.h
+++ b/chrome/test/unit/chrome_test_suite.h
@@ -15,6 +15,7 @@
 #include "base/path_service.h"
 #include "base/test/test_suite.h"
 #include "chrome/app/scoped_ole_initializer.h"
+#include "chrome/browser/chrome_content_browser_client.h"
 #include "chrome/common/chrome_content_client.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "net/base/mock_host_resolver.h"
@@ -55,6 +56,7 @@ class ChromeTestSuite : public base::TestSuite {
 
   // Client for embedding content in Chrome.
   chrome::ChromeContentClient chrome_content_client_;
+  chrome::ChromeContentBrowserClient chrome_browser_content_client_;
 
   base::StatsTable* stats_table_;
 
diff --git a/content/browser/DEPS b/content/browser/DEPS
index ed03eca..eb0e8c0 100644
--- a/content/browser/DEPS
+++ b/content/browser/DEPS
@@ -1,4 +1,8 @@
 include_rules = [

+  # The following directories have been refactored, so no new dependencies

+  # should be added from these directories.

+  "-chrome/browser/extensions",

+

   "+content/gpu",  # For single-process mode.

 ]

 

diff --git a/content/browser/content_browser_client.cc b/content/browser/content_browser_client.cc
index b96b55e..5b763c2b 100644
--- a/content/browser/content_browser_client.cc
+++ b/content/browser/content_browser_client.cc
@@ -6,6 +6,7 @@
 
 #include "base/memory/singleton.h"
 #include "content/browser/webui/empty_web_ui_factory.h"
+#include "googleurl/src/gurl.h"
 
 namespace content {
 
@@ -14,4 +15,8 @@ WebUIFactory* ContentBrowserClient::GetWebUIFactory() {
   return EmptyWebUIFactory::Get();
 }
 
+GURL ContentBrowserClient::GetEffectiveURL(Profile* profile, const GURL& url) {
+  return url;
+}
+
 }  // namespace content
diff --git a/content/browser/content_browser_client.h b/content/browser/content_browser_client.h
index c7218f8..e8350e6 100644
--- a/content/browser/content_browser_client.h
+++ b/content/browser/content_browser_client.h
@@ -26,6 +26,10 @@ class ContentBrowserClient {
 
   // Gets the WebUIFactory which will be responsible for generating WebUIs.
   virtual WebUIFactory* GetWebUIFactory();
+
+  // Get the effective URL for the given actual URL, to allow an embedder to
+  // group different url schemes in the same SiteInstance.
+  virtual GURL GetEffectiveURL(Profile* profile, const GURL& url);
 };
 
 }  // namespace content
diff --git a/content/browser/in_process_webkit/webkit_context_unittest.cc b/content/browser/in_process_webkit/webkit_context_unittest.cc
index 09ce976..5232757 100644
--- a/content/browser/in_process_webkit/webkit_context_unittest.cc
+++ b/content/browser/in_process_webkit/webkit_context_unittest.cc
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/extensions/extension_special_storage_policy.h"
 #include "chrome/test/testing_profile.h"
 #include "content/browser/browser_thread.h"
 #include "content/browser/in_process_webkit/dom_storage_context.h"
@@ -11,8 +10,9 @@
 
 class MockDOMStorageContext : public DOMStorageContext {
  public:
-  explicit MockDOMStorageContext(WebKitContext* webkit_context)
-      : DOMStorageContext(webkit_context, new ExtensionSpecialStoragePolicy),
+  MockDOMStorageContext(WebKitContext* webkit_context,
+                        quota::SpecialStoragePolicy* special_storage_policy)
+      : DOMStorageContext(webkit_context, special_storage_policy),
         purge_count_(0) {
   }
 
@@ -32,14 +32,14 @@ TEST(WebKitContextTest, Basic) {
   TestingProfile profile;
   scoped_refptr<WebKitContext> context1(new WebKitContext(
           profile.IsOffTheRecord(), profile.GetPath(),
-          profile.GetExtensionSpecialStoragePolicy(),
+          profile.GetSpecialStoragePolicy(),
           false));
   EXPECT_TRUE(profile.GetPath() == context1->data_path());
   EXPECT_TRUE(profile.IsOffTheRecord() == context1->is_incognito());
 
   scoped_refptr<WebKitContext> context2(new WebKitContext(
           profile.IsOffTheRecord(), profile.GetPath(),
-          profile.GetExtensionSpecialStoragePolicy(),
+          profile.GetSpecialStoragePolicy(),
           false));
   EXPECT_TRUE(context1->data_path() == context2->data_path());
   EXPECT_TRUE(context1->is_incognito() == context2->is_incognito());
@@ -55,10 +55,10 @@ TEST(WebKitContextTest, PurgeMemory) {
   TestingProfile profile;
   scoped_refptr<WebKitContext> context(new WebKitContext(
           profile.IsOffTheRecord(), profile.GetPath(),
-          profile.GetExtensionSpecialStoragePolicy(),
+          profile.GetSpecialStoragePolicy(),
           false));
-  MockDOMStorageContext* mock_context =
-      new MockDOMStorageContext(context.get());
+  MockDOMStorageContext* mock_context = new MockDOMStorageContext(
+      context.get(), profile.GetSpecialStoragePolicy());
   context->set_dom_storage_context(mock_context);  // Takes ownership.
 
   // Ensure PurgeMemory() calls our mock object on the right thread.
diff --git a/content/browser/plugin_service.cc b/content/browser/plugin_service.cc
index c604040..7f96deb 100644
--- a/content/browser/plugin_service.cc
+++ b/content/browser/plugin_service.cc
@@ -15,7 +15,6 @@
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/plugin_updater.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_paths.h"
diff --git a/content/browser/renderer_host/render_view_host.cc b/content/browser/renderer_host/render_view_host.cc
index b946cf8..461a9fd 100644
--- a/content/browser/renderer_host/render_view_host.cc
+++ b/content/browser/renderer_host/render_view_host.cc
@@ -16,7 +16,6 @@
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/dom_operation_notification_details.h"
-#include "chrome/browser/extensions/extension_message_service.h"
 #include "chrome/browser/metrics/user_metrics.h"
 #include "chrome/browser/net/predictor_api.h"
 #include "chrome/browser/profiles/profile.h"
@@ -772,7 +771,6 @@ bool RenderViewHost::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(ViewHostMsg_ShouldClose_ACK, OnMsgShouldCloseACK)
     IPC_MESSAGE_HANDLER(ExtensionHostMsg_Request, OnExtensionRequest)
     IPC_MESSAGE_HANDLER(ViewHostMsg_SelectionChanged, OnMsgSelectionChanged)
-    IPC_MESSAGE_HANDLER(ExtensionHostMsg_PostMessage, OnExtensionPostMessage)
     IPC_MESSAGE_HANDLER(ViewHostMsg_AccessibilityNotifications,
                         OnAccessibilityNotifications)
     IPC_MESSAGE_HANDLER(ViewHostMsg_OnCSSInserted, OnCSSInserted)
@@ -1501,14 +1499,6 @@ void RenderViewHost::JavaScriptStressTestControl(int cmd, int param) {
   Send(new ViewMsg_JavaScriptStressTestControl(routing_id(), cmd, param));
 }
 
-void RenderViewHost::OnExtensionPostMessage(
-    int port_id, const std::string& message) {
-  if (process()->profile()->GetExtensionMessageService()) {
-    process()->profile()->GetExtensionMessageService()->
-        PostMessageFromRenderer(port_id, message);
-  }
-}
-
 void RenderViewHost::OnAccessibilityNotifications(
     const std::vector<ViewHostMsg_AccessibilityNotification_Params>& params) {
   if (view())
diff --git a/content/browser/renderer_host/render_view_host.h b/content/browser/renderer_host/render_view_host.h
index c53db07..ff675a0 100644
--- a/content/browser/renderer_host/render_view_host.h
+++ b/content/browser/renderer_host/render_view_host.h
@@ -594,7 +594,6 @@ class RenderViewHost : public RenderWidgetHost {
   void OnMsgShouldCloseACK(bool proceed);
 
   void OnExtensionRequest(const ExtensionHostMsg_DomMessage_Params& params);
-  void OnExtensionPostMessage(int port_id, const std::string& message);
   void OnAccessibilityNotifications(
       const std::vector<ViewHostMsg_AccessibilityNotification_Params>& params);
   void OnCSSInserted();
diff --git a/content/browser/renderer_host/render_view_host_manager_browsertest.cc b/content/browser/renderer_host/render_view_host_manager_browsertest.cc
index d039454..059e6a3 100644
--- a/content/browser/renderer_host/render_view_host_manager_browsertest.cc
+++ b/content/browser/renderer_host/render_view_host_manager_browsertest.cc
@@ -6,7 +6,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
 #include "chrome/browser/download/download_manager.h"
-#include "chrome/browser/extensions/extension_error_reporter.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_paths.h"
diff --git a/content/browser/renderer_host/test_render_view_host.cc b/content/browser/renderer_host/test_render_view_host.cc
index 003766f..b7842cf 100644
--- a/content/browser/renderer_host/test_render_view_host.cc
+++ b/content/browser/renderer_host/test_render_view_host.cc
@@ -338,9 +338,6 @@ void RenderViewHostTestHarness::Reload() {
 }
 
 void RenderViewHostTestHarness::SetUp() {
-  // Initialize Chrome's ContentBrowserClient here, since we won't go through
-  // BrowserMain.
-  content::GetContentClient()->set_browser(&browser_client_);
   contents_.reset(CreateTestTabContents());
 }
 
diff --git a/content/browser/renderer_host/test_render_view_host.h b/content/browser/renderer_host/test_render_view_host.h
index c51296d..927af93 100644
--- a/content/browser/renderer_host/test_render_view_host.h
+++ b/content/browser/renderer_host/test_render_view_host.h
@@ -10,7 +10,6 @@
 #include "base/gtest_prod_util.h"
 #include "base/message_loop.h"
 #include "build/build_config.h"
-#include "chrome/browser/chrome_content_browser_client.h"
 #include "content/browser/renderer_host/mock_render_process_host.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
@@ -303,7 +302,6 @@ class RenderViewHostTestHarness : public testing::Test {
   MockRenderProcessHostFactory rph_factory_;
   TestRenderViewHostFactory rvh_factory_;
 
-  chrome::ChromeContentBrowserClient browser_client_;
   scoped_ptr<TestTabContents> contents_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostTestHarness);
diff --git a/content/browser/site_instance.cc b/content/browser/site_instance.cc
index 26565a1..3503eac 100644
--- a/content/browser/site_instance.cc
+++ b/content/browser/site_instance.cc
@@ -4,7 +4,6 @@
 
 #include "content/browser/site_instance.h"
 
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/browsing_instance.h"
@@ -190,18 +189,7 @@ bool SiteInstance::IsSameWebSite(Profile* profile,
 
 /*static*/
 GURL SiteInstance::GetEffectiveURL(Profile* profile, const GURL& url) {
-  if (!profile || !profile->GetExtensionService())
-    return url;
-
-  const Extension* extension =
-      profile->GetExtensionService()->GetExtensionByWebExtent(url);
-  if (extension) {
-    // If the URL is part of an extension's web extent, convert it to an
-    // extension URL.
-    return extension->GetResourceURL(url.path());
-  } else {
-    return url;
-  }
+  return content::GetContentClient()->browser()->GetEffectiveURL(profile, url);
 }
 
 /*static*/
diff --git a/content/browser/site_instance.h b/content/browser/site_instance.h
index 1c41abd2..76f966e 100644
--- a/content/browser/site_instance.h
+++ b/content/browser/site_instance.h
@@ -149,10 +149,7 @@ class SiteInstance : public base::RefCounted<SiteInstance>,
   // GetRelatedSiteInstance instead.
   explicit SiteInstance(BrowsingInstance* browsing_instance);
 
-  // Get the effective URL for the given actual URL. If the URL is part of an
-  // installed app, the effective URL is an extension URL with the ID of that
-  // extension as the host. This has the effect of grouping apps together in
-  // a common SiteInstance.
+  // Get the effective URL for the given actual URL.
   static GURL GetEffectiveURL(Profile* profile, const GURL& url);
 
   // Returns the type of renderer process this instance belongs in, for grouping
diff --git a/content/browser/site_instance_unittest.cc b/content/browser/site_instance_unittest.cc
index 247dd13..5ba3919 100644
--- a/content/browser/site_instance_unittest.cc
+++ b/content/browser/site_instance_unittest.cc
@@ -50,14 +50,23 @@ class SiteInstanceTestBrowserClient : public content::ContentBrowserClient {
 
 class SiteInstanceTest : public testing::Test {
  public:
+  SiteInstanceTest() : old_browser_client_(NULL) {
+  }
+
   virtual void SetUp() {
+    old_browser_client_ = content::GetContentClient()->browser();
     content::GetContentClient()->set_browser(&browser_client_);
   }
 
+  virtual void TearDown() {
+    content::GetContentClient()->set_browser(old_browser_client_);
+  }
+
  private:
   MessageLoopForUI message_loop_;
 
   SiteInstanceTestBrowserClient browser_client_;
+  content::ContentBrowserClient* old_browser_client_;
 };
 
 class TestBrowsingInstance : public BrowsingInstance {
diff --git a/content/browser/tab_contents/tab_contents.cc b/content/browser/tab_contents/tab_contents.cc
index 9559db3..5940baf 100644
--- a/content/browser/tab_contents/tab_contents.cc
+++ b/content/browser/tab_contents/tab_contents.cc
@@ -7,6 +7,7 @@
 #include <cmath>
 
 #include "base/auto_reset.h"
+#include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/stats_counters.h"
 #include "base/string16.h"
@@ -26,7 +27,6 @@
 #include "chrome/browser/download/download_item_model.h"
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/download/download_request_limiter.h"
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/external_protocol_handler.h"
 #include "chrome/browser/favicon_service.h"
 #include "chrome/browser/google/google_util.h"
@@ -40,6 +40,7 @@
 #include "chrome/browser/pdf_unsupported_feature.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/plugin_observer.h"
+#include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_host/web_cache_manager.h"
 #include "chrome/browser/renderer_preferences_util.h"
@@ -56,10 +57,7 @@
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/content_restriction.h"
 #include "chrome/common/extensions/extension.h"
-#include "chrome/common/extensions/extension_action.h"
-#include "chrome/common/extensions/extension_icon_set.h"
 #include "chrome/common/extensions/extension_messages.h"
-#include "chrome/common/extensions/extension_resource.h"
 #include "chrome/common/extensions/url_pattern.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/render_messages.h"
@@ -243,7 +241,6 @@ TabContents::TabContents(Profile* profile,
       all_contents_blocked_(false),
       dont_notify_render_view_(false),
       displayed_insecure_content_(false),
-      extension_app_(NULL),
       capturing_contents_(false),
       is_being_destroyed_(false),
       notify_disconnection_(false),
@@ -451,39 +448,6 @@ RenderProcessHost* TabContents::GetRenderProcessHost() const {
   return render_manager_.current_host()->process();
 }
 
-void TabContents::SetExtensionApp(const Extension* extension) {
-  DCHECK(!extension || extension->GetFullLaunchURL().is_valid());
-  extension_app_ = extension;
-
-  UpdateExtensionAppIcon(extension_app_);
-
-  NotificationService::current()->Notify(
-      NotificationType::TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED,
-      Source<TabContents>(this),
-      NotificationService::NoDetails());
-}
-
-void TabContents::SetExtensionAppById(const std::string& extension_app_id) {
-  if (extension_app_id.empty())
-    return;
-
-  ExtensionService* extension_service = profile()->GetExtensionService();
-  if (!extension_service || !extension_service->is_ready())
-    return;
-
-  const Extension* extension =
-      extension_service->GetExtensionById(extension_app_id, false);
-  if (extension)
-    SetExtensionApp(extension);
-}
-
-SkBitmap* TabContents::GetExtensionAppIcon() {
-  if (extension_app_icon_.empty())
-    return NULL;
-
-  return &extension_app_icon_;
-}
-
 const GURL& TabContents::GetURL() const {
   // We may not have a navigation entry yet
   NavigationEntry* entry = controller_.GetActiveEntry();
@@ -614,10 +578,6 @@ void TabContents::SetIsCrashed(base::TerminationStatus status, int error_code) {
   NotifyNavigationStateChanged(INVALIDATE_TAB);
 }
 
-void TabContents::PageActionStateChanged() {
-  NotifyNavigationStateChanged(TabContents::INVALIDATE_PAGE_ACTIONS);
-}
-
 void TabContents::NotifyNavigationStateChanged(unsigned changed_flags) {
   if (delegate_)
     delegate_->NavigationStateChanged(this, changed_flags);
@@ -782,8 +742,6 @@ TabContents* TabContents::Clone() {
                                     SiteInstance::CreateSiteInstance(profile()),
                                     MSG_ROUTING_NONE, this, NULL);
   tc->controller().CopyStateFrom(controller_);
-  tc->extension_app_ = extension_app_;
-  tc->extension_app_icon_ = extension_app_icon_;
   return tc;
 }
 
@@ -1639,28 +1597,6 @@ void TabContents::DidNavigateMainFramePostCommit(
   // Clear all page actions, blocked content notifications and browser actions
   // for this tab, unless this is an in-page navigation.
   if (!details.is_in_page) {
-    ExtensionService* service = profile()->GetExtensionService();
-    if (service) {
-      for (size_t i = 0; i < service->extensions()->size(); ++i) {
-        ExtensionAction* browser_action =
-            service->extensions()->at(i)->browser_action();
-        if (browser_action) {
-          browser_action->ClearAllValuesForTab(controller().session_id().id());
-          NotificationService::current()->Notify(
-              NotificationType::EXTENSION_BROWSER_ACTION_UPDATED,
-              Source<ExtensionAction>(browser_action),
-              NotificationService::NoDetails());
-        }
-
-        ExtensionAction* page_action =
-            service->extensions()->at(i)->page_action();
-        if (page_action) {
-          page_action->ClearAllValuesForTab(controller().session_id().id());
-          PageActionStateChanged();
-        }
-      }
-    }
-
     // Close blocked popups.
     if (blocked_contents_) {
       AutoReset<bool> auto_reset(&dont_notify_render_view_, true);
@@ -2667,42 +2603,6 @@ void TabContents::Observe(NotificationType type,
   }
 }
 
-void TabContents::UpdateExtensionAppIcon(const Extension* extension) {
-  extension_app_icon_.reset();
-
-  if (extension) {
-    extension_app_image_loader_.reset(new ImageLoadingTracker(this));
-    extension_app_image_loader_->LoadImage(
-        extension,
-        extension->GetIconResource(Extension::EXTENSION_ICON_SMALLISH,
-                                   ExtensionIconSet::MATCH_EXACTLY),
-        gfx::Size(Extension::EXTENSION_ICON_SMALLISH,
-                  Extension::EXTENSION_ICON_SMALLISH),
-        ImageLoadingTracker::CACHE);
-  } else {
-    extension_app_image_loader_.reset(NULL);
-  }
-}
-
-const Extension* TabContents::GetExtensionContaining(const GURL& url) {
-  ExtensionService* extensions_service = profile()->GetExtensionService();
-  if (!extensions_service)
-    return NULL;
-
-  const Extension* extension = extensions_service->GetExtensionByURL(url);
-  return extension ?
-      extension : extensions_service->GetExtensionByWebExtent(url);
-}
-
-void TabContents::OnImageLoaded(SkBitmap* image,
-                                const ExtensionResource& resource,
-                                int index) {
-  if (image) {
-    extension_app_icon_ = *image;
-    NotifyNavigationStateChanged(INVALIDATE_TAB);
-  }
-}
-
 gfx::NativeWindow TabContents::GetMessageBoxRootWindow() {
   return view_->GetTopLevelNativeWindow();
 }
diff --git a/content/browser/tab_contents/tab_contents.h b/content/browser/tab_contents/tab_contents.h
index 9ec2b39..33ca959 100644
--- a/content/browser/tab_contents/tab_contents.h
+++ b/content/browser/tab_contents/tab_contents.h
@@ -16,7 +16,6 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "chrome/browser/download/save_package.h"
-#include "chrome/browser/extensions/image_loading_tracker.h"
 #include "chrome/browser/favicon_helper.h"
 #include "chrome/browser/prefs/pref_change_registrar.h"
 #include "chrome/browser/tab_contents/tab_specific_content_settings.h"
@@ -92,7 +91,6 @@ class TabContents : public PageNavigator,
                     public RenderViewHostDelegate,
                     public RenderViewHostManager::Delegate,
                     public JavaScriptAppModalDialogDelegate,
-                    public ImageLoadingTracker::Observer,
                     public TabSpecificContentSettings::Delegate,
                     public net::NetworkChangeNotifier::OnlineStateObserver {
  public:
@@ -179,32 +177,6 @@ class TabContents : public PageNavigator,
     return *favicon_helper_.get();
   }
 
-  // App extensions ------------------------------------------------------------
-
-  // Sets the extension denoting this as an app. If |extension| is non-null this
-  // tab becomes an app-tab. TabContents does not listen for unload events for
-  // the extension. It's up to consumers of TabContents to do that.
-  //
-  // NOTE: this should only be manipulated before the tab is added to a browser.
-  // TODO(sky): resolve if this is the right way to identify an app tab. If it
-  // is, than this should be passed in the constructor.
-  void SetExtensionApp(const Extension* extension);
-
-  // Convenience for setting the app extension by id. This does nothing if
-  // |extension_app_id| is empty, or an extension can't be found given the
-  // specified id.
-  void SetExtensionAppById(const std::string& extension_app_id);
-
-  const Extension* extension_app() const { return extension_app_; }
-  bool is_app() const { return extension_app_ != NULL; }
-
-  // If an app extension has been explicitly set for this TabContents its icon
-  // is returned.
-  //
-  // NOTE: the returned icon is larger than 16x16 (its size is
-  // Extension::EXTENSION_ICON_SMALLISH).
-  SkBitmap* GetExtensionAppIcon();
-
   // Tab navigation state ------------------------------------------------------
 
   // Returns the current navigation properties, which if a navigation is
@@ -303,9 +275,6 @@ class TabContents : public PageNavigator,
   int crashed_error_code() const { return crashed_error_code_; }
   void SetIsCrashed(base::TerminationStatus status, int error_code);
 
-  // Call this after updating a page action to notify clients about the changes.
-  void PageActionStateChanged();
-
   // Whether the tab is in the process of being destroyed.
   // Added as a tentative work-around for focus related bug #4633.  This allows
   // us not to store focus when a tab is being closed.
@@ -979,19 +948,6 @@ class TabContents : public PageNavigator,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
-  // App extensions related methods:
-
-  // Returns the first extension whose extent contains |url|.
-  const Extension* GetExtensionContaining(const GURL& url);
-
-  // Resets app_icon_ and if |extension| is non-null creates a new
-  // ImageLoadingTracker to load the extension's image.
-  void UpdateExtensionAppIcon(const Extension* extension);
-
-  // ImageLoadingTracker::Observer.
-  virtual void OnImageLoaded(SkBitmap* image, const ExtensionResource& resource,
-                             int index);
-
   // NetworkChangeNotifier::OnlineStateObserver:
   virtual void OnOnlineStateChanged(bool online);
 
@@ -1116,18 +1072,6 @@ class TabContents : public PageNavigator,
   // Delegates for InfoBars associated with this TabContents.
   std::vector<InfoBarDelegate*> infobar_delegates_;
 
-  // Data for app extensions ---------------------------------------------------
-
-  // If non-null this tab is an app tab and this is the extension the tab was
-  // created for.
-  const Extension* extension_app_;
-
-  // Icon for extension_app_ (if non-null) or extension_for_current_page_.
-  SkBitmap extension_app_icon_;
-
-  // Used for loading extension_app_icon_.
-  scoped_ptr<ImageLoadingTracker> extension_app_image_loader_;
-
   // Data for misc internal state ----------------------------------------------
 
   // See capturing_contents() above.
diff --git a/content/browser/webui/web_ui_factory.cc b/content/browser/webui/web_ui_factory.cc
index 63a8c8e..230911b 100644
--- a/content/browser/webui/web_ui_factory.cc
+++ b/content/browser/webui/web_ui_factory.cc
@@ -5,7 +5,6 @@
 #include "content/browser/webui/web_ui_factory.h"
 
 #include "content/browser/content_browser_client.h"
-#include "content/common/content_client.h"
 
 namespace content {
 
diff --git a/content/common/notification_type.h b/content/common/notification_type.h
index 20edba4..b7d7fd2 100644
--- a/content/common/notification_type.h
+++ b/content/common/notification_type.h
@@ -399,7 +399,7 @@ class NotificationType {
     TAB_CONTENTS_DESTROYED,
 
     // This notification is sent when TabContents::SetAppExtension is invoked.
-    // The source is the TabContents SetAppExtension was invoked on.
+    // The source is the ExtensionTabHelper SetAppExtension was invoked on.
     TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED,
 
     // A RenderViewHost was created for a TabContents. The source is the