Refactor ExtensionView to support a UI-less extension instance.

- Introduce ExtensionHost, which is the guy that talks to the RenderViewHost.
- ExtensionView holds an ExtensionHost, and also renders its contents in an
  HWND.
- Added code to load a page optionally specified in the manifest as a
  background process whenever it exists.
Review URL: http://codereview.chromium.org/92043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@14902 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 529 insertions, 238 deletions

diff --git a/chrome/browser/browser.vcproj b/chrome/browser/browser.vcproj
index 96114e4..88150e2 100644
--- a/chrome/browser/browser.vcproj
+++ b/chrome/browser/browser.vcproj
@@ -1958,6 +1958,14 @@
 				>
 			</File>
 			<File
+				RelativePath=".\extensions\extension_host.cc"
+				>
+			</File>
+			<File
+				RelativePath=".\extensions\extension_host.h"
+				>
+			</File>
+			<File
 				RelativePath=".\extensions\extension_message_service.cc"
 				>
 			</File>
diff --git a/chrome/browser/browser_list.cc b/chrome/browser/browser_list.cc
index ca2963f..c1676c0 100644
--- a/chrome/browser/browser_list.cc
+++ b/chrome/browser/browser_list.cc
@@ -223,6 +223,23 @@ Browser* BrowserList::FindBrowserWithType(Profile* p, Browser::Type t) {
 }
 
 // static
+Browser* BrowserList::FindBrowserWithProfile(Profile* p) {
+  Browser* last_active = GetLastActive();
+  if (last_active && last_active->profile() == p)
+    return last_active;
+
+  BrowserList::const_iterator i;
+  for (i = BrowserList::begin(); i != BrowserList::end(); ++i) {
+    if (*i == last_active)
+      continue;
+
+    if ((*i)->profile() == p)
+      return *i;
+  }
+  return NULL;
+}
+
+// static
 Browser* BrowserList::FindBrowserWithID(SessionID::id_type desired_id) {
   BrowserList::const_iterator i;
   for (i = BrowserList::begin(); i != BrowserList::end(); ++i) {
diff --git a/chrome/browser/browser_list.h b/chrome/browser/browser_list.h
index 2488a09..faa2f64 100644
--- a/chrome/browser/browser_list.h
+++ b/chrome/browser/browser_list.h
@@ -59,6 +59,11 @@ class BrowserList {
   // is returned. Returns NULL if no such browser currently exists.
   static Browser* FindBrowserWithType(Profile* p, Browser::Type t);
 
+  // Find an existing browser window with the provided profile. If the last
+  // active has the right profile, it is returned.  Returns NULL if no such
+  // browser currently exists.
+  static Browser* FindBrowserWithProfile(Profile* p);
+
   // Find an existing browser with the provided ID. Returns NULL if no such
   // browser currently exists.
   static Browser* FindBrowserWithID(SessionID::id_type desired_id);
diff --git a/chrome/browser/extensions/extension.cc b/chrome/browser/extensions/extension.cc
index 1aeaeaa..6b2bb3e 100644
--- a/chrome/browser/extensions/extension.cc
+++ b/chrome/browser/extensions/extension.cc
@@ -24,6 +24,7 @@ const wchar_t* Extension::kMatchesKey = L"matches";
 const wchar_t* Extension::kNameKey = L"name";
 const wchar_t* Extension::kPermissionsKey = L"permissions";
 const wchar_t* Extension::kPluginsDirKey = L"plugins_dir";
+const wchar_t* Extension::kBackgroundKey = L"background";
 const wchar_t* Extension::kRunAtKey = L"run_at";
 const wchar_t* Extension::kThemeKey = L"theme";
 const wchar_t* Extension::kToolstripsKey = L"toolstrips";
@@ -75,6 +76,8 @@ const char* Extension::kInvalidPermissionSchemeError =
     "allowed.";
 const char* Extension::kInvalidPluginsDirError =
     "Invalid value for 'plugins_dir'.";
+const char* Extension::kInvalidBackgroundError =
+    "Invalid value for 'background'.";
 const char* Extension::kInvalidRunAtError =
     "Invalid value for 'content_scripts[*].run_at'.";
 const char* Extension::kInvalidToolstripError =
@@ -403,6 +406,16 @@ bool Extension::InitFromValue(const DictionaryValue& source, bool require_id,
     plugins_dir_ = path_.AppendASCII(plugins_dir);
   }
 
+  // Initialize background url (optional).
+  if (source.HasKey(kBackgroundKey)) {
+    std::string background_str;
+    if (!source.GetString(kBackgroundKey, &background_str)) {
+      *error = kInvalidBackgroundError;
+      return false;
+    }
+    background_url_ = GetResourceURL(background_str);
+  }
+
   // Initialize toolstrips (optional).
   if (source.HasKey(kToolstripsKey)) {
     ListValue* list_value;
diff --git a/chrome/browser/extensions/extension.h b/chrome/browser/extensions/extension.h
index 2f59115..95f04bb 100644
--- a/chrome/browser/extensions/extension.h
+++ b/chrome/browser/extensions/extension.h
@@ -38,6 +38,7 @@ class Extension {
   static const wchar_t* kNameKey;
   static const wchar_t* kPermissionsKey;
   static const wchar_t* kPluginsDirKey;
+  static const wchar_t* kBackgroundKey;
   static const wchar_t* kRunAtKey;
   static const wchar_t* kThemeKey;
   static const wchar_t* kToolstripsKey;
@@ -63,6 +64,7 @@ class Extension {
   static const char* kInvalidMatchesError;
   static const char* kInvalidNameError;
   static const char* kInvalidPluginsDirError;
+  static const char* kInvalidBackgroundError;
   static const char* kInvalidRunAtError;
   static const char* kInvalidToolstripError;
   static const char* kInvalidToolstripsError;
@@ -122,6 +124,7 @@ class Extension {
   const std::string& description() const { return description_; }
   const UserScriptList& content_scripts() const { return content_scripts_; }
   const FilePath& plugins_dir() const { return plugins_dir_; }
+  const GURL& background_url() const { return background_url_; }
   const std::vector<std::string>& toolstrips() const { return toolstrips_; }
   const std::vector<URLPattern>& permissions() const {
       return permissions_; }
@@ -163,6 +166,10 @@ class Extension {
   // contains.
   FilePath plugins_dir_;
 
+  // Optional URL to a master page of which a single instance should be always
+  // loaded in the background.
+  GURL background_url_;
+
   // Paths to HTML files to be displayed in the toolbar.
   std::vector<std::string> toolstrips_;
 
@@ -174,6 +181,7 @@ class Extension {
   // A map of resource id's to relative file paths.
   std::map<const std::wstring, std::string> theme_paths_;
 
+  // The sites this extension has permission to talk to (using XHR, etc).
   std::vector<URLPattern> permissions_;
 
   // We implement copy, but not assign.
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
new file mode 100755
index 0000000..16d55e8
--- /dev/null
+++ b/chrome/browser/extensions/extension_host.cc
@@ -0,0 +1,171 @@
+// Copyright (c) 2006-2009 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.
+
+#include "chrome/browser/extensions/extension_host.h"
+
+#include "chrome/browser/browser.h"
+#include "chrome/browser/browser_list.h"
+#include "chrome/browser/extensions/extension.h"
+#include "chrome/browser/extensions/extension_message_service.h"
+#include "chrome/browser/extensions/extension_view.h"
+#include "chrome/browser/profile.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/renderer_host/render_process_host.h"
+#include "chrome/browser/renderer_host/render_widget_host.h"
+#include "chrome/browser/renderer_host/render_widget_host_view.h"
+#include "chrome/browser/tab_contents/site_instance.h"
+#include "chrome/browser/tab_contents/web_contents.h"
+#include "chrome/browser/tab_contents/tab_contents_view.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/common/pref_service.h"
+#include "chrome/common/resource_bundle.h"
+
+#include "grit/browser_resources.h"
+#include "grit/generated_resources.h"
+
+#include "webkit/glue/context_menu.h"
+
+ExtensionHost::ExtensionHost(Extension* extension, SiteInstance* site_instance)
+    : extension_(extension), view_(NULL), did_stop_loading_(false) {
+  render_view_host_ = new RenderViewHost(
+      site_instance, this, MSG_ROUTING_NONE, NULL);
+  render_view_host_->AllowExtensionBindings();
+}
+
+ExtensionHost::~ExtensionHost() {
+  render_view_host_->Shutdown();  // deletes render_view_host
+}
+
+SiteInstance* ExtensionHost::site_instance() const {
+  return render_view_host_->site_instance();
+}
+
+void ExtensionHost::CreateRenderView(const GURL& url,
+                                     RenderWidgetHostView* host_view) {
+  render_view_host_->set_view(host_view);
+  render_view_host_->CreateRenderView();
+  render_view_host_->NavigateToURL(url);
+}
+
+void ExtensionHost::DidContentsPreferredWidthChange(const int pref_width) {
+  if (view_)
+    view_->DidContentsPreferredWidthChange(pref_width);
+}
+
+void ExtensionHost::RenderViewCreated(RenderViewHost* rvh) {
+  URLRequestContext* context = rvh->process()->profile()->GetRequestContext();
+  ExtensionMessageService::GetInstance(context)->RegisterExtension(
+      extension_->id(), rvh->process()->pid());
+}
+
+WebPreferences ExtensionHost::GetWebkitPrefs() {
+  PrefService* prefs = render_view_host()->process()->profile()->GetPrefs();
+  const bool kIsDomUI = true;
+  return RenderViewHostDelegateHelper::GetWebkitPrefs(prefs, kIsDomUI);
+}
+
+void ExtensionHost::RunJavaScriptMessage(
+    const std::wstring& message,
+    const std::wstring& default_prompt,
+    const GURL& frame_url,
+    const int flags,
+    IPC::Message* reply_msg,
+    bool* did_suppress_message) {
+  // Automatically cancel the javascript alert (otherwise the renderer hangs
+  // indefinitely).
+  *did_suppress_message = true;
+  render_view_host()->JavaScriptMessageBoxClosed(reply_msg, true, L"");
+}
+
+void ExtensionHost::DidStartLoading(RenderViewHost* render_view_host) {
+  static const StringPiece toolstrip_css(
+      ResourceBundle::GetSharedInstance().GetRawDataResource(
+          IDR_EXTENSIONS_TOOLSTRIP_CSS));
+  render_view_host->InsertCSSInWebFrame(L"", toolstrip_css.as_string());
+}
+
+void ExtensionHost::DidStopLoading(RenderViewHost* render_view_host) {
+  render_view_host->WasResized();
+  did_stop_loading_ = true;
+  if (view_)
+    view_->ShowIfCompletelyLoaded();
+}
+
+ExtensionFunctionDispatcher* ExtensionHost::
+    CreateExtensionFunctionDispatcher(RenderViewHost *render_view_host,
+                                      const std::string& extension_id) {
+  return new ExtensionFunctionDispatcher(render_view_host, GetBrowser(),
+                                         extension_id);
+}
+
+RenderViewHostDelegate::View* ExtensionHost::GetViewDelegate() const {
+  // TODO(erikkay) this is unfortunate.  The interface declares that this method
+  // must be const (no good reason for it as far as I can tell) which means you
+  // can't return self without doing this const_cast.  Either we need to change
+  // the interface, or we need to split out the view delegate into another
+  // object (which is how WebContents works).
+  return const_cast<ExtensionHost*>(this);
+}
+
+void ExtensionHost::CreateNewWindow(int route_id,
+                                    base::WaitableEvent* modal_dialog_event) {
+  delegate_view_helper_.CreateNewWindow(
+      route_id, modal_dialog_event, render_view_host()->process()->profile(),
+      site_instance());
+}
+
+void ExtensionHost::CreateNewWidget(int route_id, bool activatable) {
+  delegate_view_helper_.CreateNewWidget(route_id, activatable,
+                                        site_instance()->GetProcess());
+}
+
+void ExtensionHost::ShowCreatedWindow(int route_id,
+                                      WindowOpenDisposition disposition,
+                                      const gfx::Rect& initial_pos,
+                                      bool user_gesture) {
+  WebContents* contents = delegate_view_helper_.GetCreatedWindow(route_id);
+  if (contents) {
+    // TODO(erikkay) is it safe to pass in NULL as source?
+    GetBrowser()->AddTabContents(contents, disposition, initial_pos,
+                                 user_gesture);
+  }
+}
+
+void ExtensionHost::ShowCreatedWidget(int route_id,
+                                      const gfx::Rect& initial_pos) {
+  RenderWidgetHostView* widget_host_view =
+      delegate_view_helper_.GetCreatedWidget(route_id);
+  GetBrowser()->BrowserRenderWidgetShowing();
+  // TODO(erikkay): These two lines could be refactored with TabContentsView.
+  widget_host_view->InitAsPopup(render_view_host()->view(), initial_pos);
+  widget_host_view->GetRenderWidgetHost()->Init();
+}
+
+void ExtensionHost::ShowContextMenu(const ContextMenuParams& params) {
+  // TODO(erikkay) - This is a temporary hack.  Show a menu here instead.
+  render_view_host()->InspectElementAt(params.x, params.y);
+}
+
+void ExtensionHost::StartDragging(const WebDropData& drop_data) {
+}
+
+void ExtensionHost::UpdateDragCursor(bool is_drop_target) {
+}
+
+void ExtensionHost::TakeFocus(bool reverse) {
+}
+
+void ExtensionHost::HandleKeyboardEvent(const NativeWebKeyboardEvent& event) {
+}
+
+Browser* ExtensionHost::GetBrowser() {
+  if (view_)
+    return view_->browser();
+  Browser* browser = BrowserList::FindBrowserWithProfile(
+      render_view_host()->process()->profile());
+  // TODO(mpcomplete): what this verifies doesn't actually happen yet.
+  CHECK(browser) << "ExtensionHost running in Profile with no Browser active."
+      " It should have been deleted.";
+  return browser;
+}
diff --git a/chrome/browser/extensions/extension_host.h b/chrome/browser/extensions/extension_host.h
new file mode 100755
index 0000000..0c67be8
--- /dev/null
+++ b/chrome/browser/extensions/extension_host.h
@@ -0,0 +1,100 @@
+// Copyright (c) 2006-2009 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_EXTENSIONS_EXTENSION_HOST_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_
+
+#include "chrome/browser/renderer_host/render_view_host_delegate.h"
+#include "chrome/browser/tab_contents/render_view_host_delegate_helper.h"
+
+class Browser;
+class Extension;
+class ExtensionView;
+class RenderWidgetHost;
+class RenderWidgetHostView;
+class WebContents;
+struct WebPreferences;
+
+// This class is the browser component of an extension component's RenderView.
+// It handles setting up the renderer process, if needed, with special
+// privileges available to extensions.  It may have a view to be shown in the
+// in the browser UI, or it may be hidden.
+class ExtensionHost : public RenderViewHostDelegate,
+                      public RenderViewHostDelegate::View {
+ public:
+  ExtensionHost(Extension* extension, SiteInstance* site_instance);
+  ~ExtensionHost();
+
+  void set_view(ExtensionView* view) { view_ = view; }
+  ExtensionView* view() const { return view_; }
+  Extension* extension() { return extension_; }
+  RenderViewHost* render_view_host() const { return render_view_host_; }
+  SiteInstance* site_instance() const;
+  bool did_stop_loading() const { return did_stop_loading_; }
+
+  // Initializes our RenderViewHost by creating its RenderView and navigating
+  // to the given URL.  Uses host_view for the RenderViewHost's view (can be
+  // NULL).
+  void CreateRenderView(const GURL& url, RenderWidgetHostView* host_view);
+
+  // RenderViewHostDelegate
+  // TODO(mpcomplete): GetProfile is unused.
+  virtual Profile* GetProfile() const { return NULL; }
+  virtual void RenderViewCreated(RenderViewHost* render_view_host);
+  virtual void DidContentsPreferredWidthChange(const int pref_width);
+  virtual WebPreferences GetWebkitPrefs();
+  virtual void RunJavaScriptMessage(
+      const std::wstring& message,
+      const std::wstring& default_prompt,
+      const GURL& frame_url,
+      const int flags,
+      IPC::Message* reply_msg,
+      bool* did_suppress_message);
+  virtual void DidStartLoading(RenderViewHost* render_view_host);
+  virtual void DidStopLoading(RenderViewHost* render_view_host);
+  virtual RenderViewHostDelegate::View* GetViewDelegate() const;
+  virtual ExtensionFunctionDispatcher* CreateExtensionFunctionDispatcher(
+      RenderViewHost *render_view_host, const std::string& extension_id);
+
+  // RenderViewHostDelegate::View
+  virtual void CreateNewWindow(int route_id,
+                               base::WaitableEvent* modal_dialog_event);
+  virtual void CreateNewWidget(int route_id, bool activatable);
+  virtual void ShowCreatedWindow(int route_id,
+                                 WindowOpenDisposition disposition,
+                                 const gfx::Rect& initial_pos,
+                                 bool user_gesture);
+  virtual void ShowCreatedWidget(int route_id,
+                                 const gfx::Rect& initial_pos);
+  virtual void ShowContextMenu(const ContextMenuParams& params);
+  virtual void StartDragging(const WebDropData& drop_data);
+  virtual void UpdateDragCursor(bool is_drop_target);
+  virtual void TakeFocus(bool reverse);
+  virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event);
+
+ private:
+  // If this ExtensionHost has a view, this returns the Browser that view is a
+  // part of.  If this is a global background page, we use the active Browser
+  // instead.
+  Browser* GetBrowser();
+
+  // The extension that we're hosting in this view.
+  Extension* extension_;
+
+  // Optional view that shows the rendered content in the UI.
+  ExtensionView* view_;
+
+  // The host for our HTML content.
+  RenderViewHost* render_view_host_;
+
+  // Common implementations of some RenderViewHostDelegate::View methods.
+  RenderViewHostDelegateViewHelper delegate_view_helper_;
+
+  // Whether the RenderWidget has reported that it has stopped loading.
+  bool did_stop_loading_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionHost);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_
diff --git a/chrome/browser/extensions/extension_view.cc b/chrome/browser/extensions/extension_view.cc
index b394af7..5678e08 100755
--- a/chrome/browser/extensions/extension_view.cc
+++ b/chrome/browser/extensions/extension_view.cc
@@ -4,65 +4,65 @@
 
 #include "chrome/browser/extensions/extension_view.h"
 
-#include "base/command_line.h"
-#include "chrome/browser/browser.h"
-#include "chrome/browser/character_encoding.h"
-#include "chrome/browser/extensions/extension.h"
-#include "chrome/browser/extensions/extension_message_service.h"
-#include "chrome/browser/jsmessage_box_handler.h"
-#include "chrome/browser/profile.h"
+#include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
-#include "chrome/browser/renderer_host/render_process_host.h"
-#include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/browser/renderer_host/render_widget_host_view.h"
-#include "chrome/browser/tab_contents/site_instance.h"
-#include "chrome/browser/tab_contents/web_contents.h"
-#include "chrome/browser/tab_contents/tab_contents_view.h"
-#include "chrome/common/chrome_switches.h"
-#include "chrome/common/pref_names.h"
-#include "chrome/common/pref_service.h"
-#include "chrome/common/resource_bundle.h"
-
-#include "grit/browser_resources.h"
-#include "grit/generated_resources.h"
-
-#include "webkit/glue/context_menu.h"
-
-ExtensionView::ExtensionView(Extension* extension,
-                             const GURL& url,
-                             SiteInstance* instance,
-                             Browser* browser)
-    : HWNDHtmlView(url, this, false, instance),
-      extension_(extension),
-      browser_(browser),
-      did_stop_loading_(false),
-      pending_preferred_width_(0) {
+#include "chrome/views/widget/widget.h"
+
+#if defined(OS_WIN)
+#include "chrome/browser/renderer_host/render_widget_host_view_win.h"
+#endif
+
+ExtensionView::ExtensionView(ExtensionHost* host, Browser* browser,
+                             const GURL& content_url)
+    : host_(host), browser_(browser), content_url_(content_url),
+      initialized_(false) {
+  host_->set_view(this);
+}
+
+ExtensionView::~ExtensionView() {
+  if (GetHWND())
+    Detach();
 }
 
-ExtensionFunctionDispatcher* ExtensionView::
-    CreateExtensionFunctionDispatcher(RenderViewHost *render_view_host,
-                                      const std::string& extension_id) {
-  return new ExtensionFunctionDispatcher(render_view_host, browser_,
-      extension_id);
+void ExtensionView::SetVisible(bool is_visible) {
+  HWNDView::SetVisible(is_visible);
+
+  // Also tell RenderWidgetHostView the new visibility. Despite its name, it is
+  // not part of the View heirarchy and does not know about the change unless we
+  // tell it.
+  if (render_view_host()->view()) {
+    if (is_visible)
+      render_view_host()->view()->Show();
+    else
+      render_view_host()->view()->Hide();
+  }
+}
+
+void ExtensionView::DidChangeBounds(const gfx::Rect& previous,
+                                    const gfx::Rect& current) {
+  // Propagate the new size to RenderWidgetHostView.
+  // We can't send size zero because RenderWidget DCHECKs that.
+  if (render_view_host()->view() && !current.IsEmpty())
+    render_view_host()->view()->SetSize(gfx::Size(width(), height()));
 }
 
 void ExtensionView::ShowIfCompletelyLoaded() {
   // We wait to show the ExtensionView until it has loaded and our parent has
   // given us a background. These can happen in different orders.
-  if (did_stop_loading_ && !render_view_host()->view()->background().empty()) {
+  if (host_->did_stop_loading() && render_view_host()->view() &&
+      !render_view_host()->view()->background().empty()) {
     SetVisible(true);
     DidContentsPreferredWidthChange(pending_preferred_width_);
   }
 }
 
 void ExtensionView::SetBackground(const SkBitmap& background) {
-  HWNDHtmlView::SetBackground(background);
-  ShowIfCompletelyLoaded();
-}
-
-void ExtensionView::DidStopLoading(RenderViewHost* render_view_host) {
-  render_view_host->WasResized();
-  did_stop_loading_ = true;
+  if (initialized_ && render_view_host()->view()) {
+    render_view_host()->view()->SetBackground(background);
+  } else {
+    pending_background_ = background;
+  }
   ShowIfCompletelyLoaded();
 }
 
@@ -87,97 +87,37 @@ void ExtensionView::DidContentsPreferredWidthChange(const int pref_width) {
   }
 }
 
-void ExtensionView::CreatingRenderer() {
-  render_view_host()->AllowExtensionBindings();
-  SetVisible(false);
-}
-
-void ExtensionView::RenderViewCreated(RenderViewHost* rvh) {
-  URLRequestContext* context = rvh->process()->profile()->GetRequestContext();
-  ExtensionMessageService::GetInstance(context)->RegisterExtension(
-      extension_->id(), render_view_host()->process()->pid());
-}
-
-WebPreferences ExtensionView::GetWebkitPrefs() {
-  PrefService* prefs = render_view_host()->process()->profile()->GetPrefs();
-  bool isDomUI = true;
-  return RenderViewHostDelegateHelper::GetWebkitPrefs(prefs, isDomUI);
-}
-
-void ExtensionView::RunJavaScriptMessage(
-    const std::wstring& message,
-    const std::wstring& default_prompt,
-    const GURL& frame_url,
-    const int flags,
-    IPC::Message* reply_msg,
-    bool* did_suppress_message) {
-  // Automatically cancel the javascript alert (otherwise the renderer hangs
-  // indefinitely).
-  *did_suppress_message = true;
-  render_view_host()->JavaScriptMessageBoxClosed(reply_msg, true, L"");
-}
-
-void ExtensionView::DidStartLoading(RenderViewHost* render_view_host) {
-  static const StringPiece toolstrip_css(
-      ResourceBundle::GetSharedInstance().GetRawDataResource(
-          IDR_EXTENSIONS_TOOLSTRIP_CSS));
-  render_view_host->InsertCSSInWebFrame(L"", toolstrip_css.as_string());
-}
-
-RenderViewHostDelegate::View* ExtensionView::GetViewDelegate() const {
-  // TODO(erikkay) this is unfortunate.  The interface declares that this method
-  // must be const (no good reason for it as far as I can tell) which means you
-  // can't return self without doing this const_cast.  Either we need to change
-  // the interface, or we need to split out the view delegate into another
-  // object (which is how WebContents works).
-  return const_cast<ExtensionView*>(this);
-}
-
-void ExtensionView::CreateNewWindow(int route_id,
-                                    base::WaitableEvent* modal_dialog_event) {
-  delegate_view_helper_.CreateNewWindow(route_id, modal_dialog_event,
-                                        browser_->profile(), site_instance());
-}
-
-void ExtensionView::CreateNewWidget(int route_id, bool activatable) {
-  delegate_view_helper_.CreateNewWidget(route_id, activatable,
-                                        site_instance()->GetProcess());
-}
-
-void ExtensionView::ShowCreatedWindow(int route_id,
-                                      WindowOpenDisposition disposition,
-                                      const gfx::Rect& initial_pos,
-                                      bool user_gesture) {
-  WebContents* contents = delegate_view_helper_.GetCreatedWindow(route_id);
-  if (contents) {
-    browser_->AddTabContents(contents, disposition, initial_pos, user_gesture);
+void ExtensionView::ViewHierarchyChanged(bool is_add,
+                                         views::View *parent,
+                                         views::View *child) {
+  if (is_add && GetWidget() && !initialized_) {
+    initialized_ = true;
+
+    RenderWidgetHostView* view = RenderWidgetHostView::CreateViewForWidget(
+        render_view_host());
+
+    // TODO(mpcomplete): RWHV needs a cross-platform Init function.
+#if defined(OS_WIN)
+    // Create the HWND. Note:
+    // RenderWidgetHostHWND supports windowed plugins, but if we ever also
+    // wanted to support constrained windows with this, we would need an
+    // additional HWND to parent off of because windowed plugin HWNDs cannot
+    // exist in the same z-order as constrained windows.
+    RenderWidgetHostViewWin* view_win =
+        static_cast<RenderWidgetHostViewWin*>(view);
+    HWND hwnd = view_win->Create(GetWidget()->GetNativeView());
+    view_win->ShowWindow(SW_SHOW);
+    Attach(hwnd);
+#else
+    NOTIMPLEMENTED();
+#endif
+
+    host_->CreateRenderView(content_url_, view);
+    SetVisible(false);
+
+    if (!pending_background_.empty()) {
+      render_view_host()->view()->SetBackground(pending_background_);
+      pending_background_.reset();
+    }
   }
 }
-
-void ExtensionView::ShowCreatedWidget(int route_id,
-                                      const gfx::Rect& initial_pos) {
-  RenderWidgetHostView* widget_host_view =
-      delegate_view_helper_.GetCreatedWidget(route_id);
-  browser_->BrowserRenderWidgetShowing();
-  // TODO(erikkay): These two lines could be refactored with TabContentsView.
-  widget_host_view->InitAsPopup(render_view_host()->view(),
-                                initial_pos);
-  widget_host_view->GetRenderWidgetHost()->Init();
-}
-
-void ExtensionView::ShowContextMenu(const ContextMenuParams& params) {
-  // TODO(erikkay) - This is a temporary hack.  Show a menu here instead.
-  render_view_host()->InspectElementAt(params.x, params.y);
-}
-
-void ExtensionView::StartDragging(const WebDropData& drop_data) {
-}
-
-void ExtensionView::UpdateDragCursor(bool is_drop_target) {
-}
-
-void ExtensionView::TakeFocus(bool reverse) {
-}
-
-void ExtensionView::HandleKeyboardEvent(const NativeWebKeyboardEvent& event) {
-}
diff --git a/chrome/browser/extensions/extension_view.h b/chrome/browser/extensions/extension_view.h
index 38e093d..7715c5b 100755
--- a/chrome/browser/extensions/extension_view.h
+++ b/chrome/browser/extensions/extension_view.h
@@ -5,97 +5,68 @@
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_VIEW_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_VIEW_H_
 
-#include "chrome/browser/renderer_host/render_view_host_delegate.h"
-#include "chrome/browser/tab_contents/render_view_host_delegate_helper.h"
+#include "build/build_config.h"
+
+#include "base/scoped_ptr.h"
+#include "chrome/browser/extensions/extension_host.h"
+#include "googleurl/src/gurl.h"
 #include "skia/include/SkBitmap.h"
 
 // TODO(port): Port these files.
 #if defined(OS_WIN)
-#include "chrome/browser/views/hwnd_html_view.h"
+#include "chrome/views/controls/hwnd_view.h"
 #else
+#include "chrome/views/view.h"
 #include "chrome/common/temp_scaffolding_stubs.h"
 #endif
 
 class Browser;
 class Extension;
-class ExtensionFunctionDispatcher;
-class RenderWidgetHost;
-class RenderWidgetHostView;
-class WebContents;
-struct WebPreferences;
-
-// This class is the browser component of an extension component's RenderView.
-// It handles setting up the renderer process, if needed, with special
-// priviliges available to extensions.  The view may be drawn to the screen or
-// hidden.
-class ExtensionView : public HWNDHtmlView,
-                      public RenderViewHostDelegate,
-                      public RenderViewHostDelegate::View {
- public:
-  // ExtensionView
-  ExtensionView(Extension* extension,
-                const GURL& url,
-                SiteInstance* instance,
-                Browser* browser);
-
-  Extension* extension() { return extension_; }
-
-  // HWNDHtmlView
-  virtual void CreatingRenderer();
-
-  virtual void SetBackground(const SkBitmap& background);
-
-  // RenderViewHostDelegate
-  // TODO(mpcomplete): GetProfile is unused.
-  virtual Profile* GetProfile() const { return NULL; }
-  virtual ExtensionFunctionDispatcher *CreateExtensionFunctionDispatcher(
-      RenderViewHost *render_view_host,
-      const std::string& extension_id);
-  virtual void RenderViewCreated(RenderViewHost* render_view_host);
-  virtual void DidContentsPreferredWidthChange(const int pref_width);
-  virtual void DidStopLoading(RenderViewHost* render_view_host);
-  virtual WebPreferences GetWebkitPrefs();
-  virtual void RunJavaScriptMessage(
-      const std::wstring& message,
-      const std::wstring& default_prompt,
-      const GURL& frame_url,
-      const int flags,
-      IPC::Message* reply_msg,
-      bool* did_suppress_message);
-  virtual void DidStartLoading(RenderViewHost* render_view_host);
-  virtual RenderViewHostDelegate::View* GetViewDelegate() const;
-
-  // RenderViewHostDelegate::View
-  virtual void CreateNewWindow(int route_id,
-                               base::WaitableEvent* modal_dialog_event);
-  virtual void CreateNewWidget(int route_id, bool activatable);
-  virtual void ShowCreatedWindow(int route_id,
-                                 WindowOpenDisposition disposition,
-                                 const gfx::Rect& initial_pos,
-                                 bool user_gesture);
-  virtual void ShowCreatedWidget(int route_id,
-                                 const gfx::Rect& initial_pos);
-  virtual void ShowContextMenu(const ContextMenuParams& params);
-  virtual void StartDragging(const WebDropData& drop_data);
-  virtual void UpdateDragCursor(bool is_drop_target);
-  virtual void TakeFocus(bool reverse);
-  virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event);
 
+// This handles the display portion of an ExtensionHost.
+class ExtensionView : public views::HWNDView {
+ public:
+  ExtensionView(ExtensionHost* host, Browser* browser, const GURL& content_url);
+  ~ExtensionView();
+
+  ExtensionHost* host() const { return host_.get(); }
+  Browser* browser() const { return browser_; }
+  Extension* extension() { return host_->extension(); }
+  RenderViewHost* render_view_host() { return host_->render_view_host(); }
+
+  // Notification from ExtensionHost.
+  void DidContentsPreferredWidthChange(const int pref_width);
+
+  // Set a custom background for the view. The background will be tiled.
+  void SetBackground(const SkBitmap& background);
+
+  // views::HWNDView
+  virtual void SetVisible(bool is_visible);
+  virtual void DidChangeBounds(const gfx::Rect& previous,
+                               const gfx::Rect& current);
+  virtual void ViewHierarchyChanged(bool is_add,
+                                    views::View *parent, views::View *child);
  private:
+  friend class ExtensionHost;
+
   // We wait to show the ExtensionView until several things have loaded.
   void ShowIfCompletelyLoaded();
 
-  // The extension that we're hosting in this view.
-  Extension* extension_;
+  // The running extension instance that we're displaying.
+  scoped_ptr<ExtensionHost> host_;
 
   // The browser window that this view is in.
   Browser* browser_;
 
-  // Common implementations of some RenderViewHostDelegate::View methods.
-  RenderViewHostDelegateViewHelper delegate_view_helper_;
+  // The URL to navigate the host to upon initialization.
+  GURL content_url_;
+
+  // True if we've been initialized.
+  bool initialized_;
 
-  // Whether the RenderWidget has reported that it has stopped loading.
-  bool did_stop_loading_;
+  // The background the view should have once it is initialized. This is set
+  // when the view has a custom background, but hasn't been initialized yet.
+  SkBitmap pending_background_;
 
   // What we should set the preferred width to once the ExtensionView has
   // loaded.
diff --git a/chrome/browser/extensions/extension_view_unittest.cc b/chrome/browser/extensions/extension_view_unittest.cc
index e1c3d8d..3529022 100755
--- a/chrome/browser/extensions/extension_view_unittest.cc
+++ b/chrome/browser/extensions/extension_view_unittest.cc
@@ -6,7 +6,7 @@
 #include "chrome/browser/browser.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/extensions/extension_error_reporter.h"
-#include "chrome/browser/extensions/extension_view.h"
+#include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extensions_service.h"
 #include "chrome/browser/extensions/test_extension_loader.h"
 #include "chrome/browser/tab_contents/site_instance.h"
@@ -28,12 +28,13 @@ const char* kExtensionId = "00123456789abcdef0123456789abcdef0123456";
 
 // This class starts up an extension process and waits until it tries to put
 // up a javascript alert.
-class MockExtensionView : public ExtensionView {
+class MockExtensionHost : public ExtensionHost {
  public:
-  MockExtensionView(Extension* extension, const GURL& url,
-                    SiteInstance* instance, Browser* browser)
-      : ExtensionView(extension, url, instance, browser), got_message_(false) {
-    InitHidden();
+  MockExtensionHost(Extension* extension, const GURL& url,
+                    SiteInstance* instance)
+      : ExtensionHost(extension, instance),
+        got_message_(false) {
+    CreateRenderView(url, NULL);
     MessageLoop::current()->PostDelayedTask(FROM_HERE,
         new MessageLoop::QuitTask, kAlertTimeoutMs);
     ui_test_utils::RunMessageLoop();
@@ -58,7 +59,7 @@ class MockExtensionView : public ExtensionView {
     MessageLoopForUI::current()->Quit();
 
     // Call super, otherwise we'll leak reply_msg.
-    ExtensionView::RunJavaScriptMessage(
+    ExtensionHost::RunJavaScriptMessage(
         message, default_prompt, frame_url, flags,
         reply_msg, did_suppress_message);
   }
@@ -100,8 +101,7 @@ IN_PROC_BROWSER_TEST_F(ExtensionViewTest, Index) {
   GURL url = Extension::GetResourceURL(extension->url(), "toolstrip1.html");
 
   // Start the extension process and wait for it to show a javascript alert.
-  MockExtensionView view(extension, url,
-      browser()->profile()->GetExtensionsService()->GetSiteInstanceForURL(url),
-      browser());
-  EXPECT_TRUE(view.got_message());
+  MockExtensionHost host(extension, url,
+      browser()->profile()->GetExtensionsService()->GetSiteInstanceForURL(url));
+  EXPECT_TRUE(host.got_message());
 }
diff --git a/chrome/browser/extensions/extensions_service.cc b/chrome/browser/extensions/extensions_service.cc
index b645dfe..38fb703 100644
--- a/chrome/browser/extensions/extensions_service.cc
+++ b/chrome/browser/extensions/extensions_service.cc
@@ -18,8 +18,9 @@
 #include "chrome/browser/extensions/extension.h"
 #include "chrome/browser/extensions/extension_browser_event_router.h"
 #include "chrome/browser/extensions/extension_error_reporter.h"
-#include "chrome/browser/extensions/user_script_master.h"
+#include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_view.h"
+#include "chrome/browser/extensions/user_script_master.h"
 #include "chrome/browser/plugin_service.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/site_instance.h"
@@ -27,6 +28,8 @@
 #include "chrome/common/notification_service.h"
 #include "chrome/common/unzip.h"
 
+#include "chrome/browser/browser_list.h"
+
 #if defined(OS_WIN)
 #include "base/registry.h"
 #endif
@@ -82,6 +85,11 @@ ExtensionsService::ExtensionsService(Profile* profile,
 }
 
 ExtensionsService::~ExtensionsService() {
+  for (ExtensionHostList::iterator iter = background_hosts_.begin();
+      iter != background_hosts_.end(); ++iter) {
+    delete *iter;
+  }
+
   for (ExtensionList::iterator iter = extensions_.begin();
        iter != extensions_.end(); ++iter) {
     delete *iter;
@@ -163,6 +171,11 @@ void ExtensionsService::OnExtensionsLoaded(ExtensionList* new_extensions) {
          script != scripts.end(); ++script) {
       user_script_master_->AddLoneScript(*script);
     }
+
+    // Start the process for the master page, if it exists.
+    if ((*extension)->background_url().is_valid()) {
+      CreateBackgroundHost(*extension, (*extension)->background_url());
+    }
   }
 
   // Since user scripts may have changed, tell UserScriptMaster to kick off
@@ -189,7 +202,16 @@ void ExtensionsService::OnExtensionInstalled(FilePath path, bool update) {
 ExtensionView* ExtensionsService::CreateView(Extension* extension,
                                              const GURL& url,
                                              Browser* browser) {
-  return new ExtensionView(extension, url, GetSiteInstanceForURL(url), browser);
+  return new ExtensionView(
+      new ExtensionHost(extension, GetSiteInstanceForURL(url)), browser, url);
+}
+
+void ExtensionsService::CreateBackgroundHost(Extension* extension,
+                                           const GURL& url) {
+  ExtensionHost* host =
+      new ExtensionHost(extension, GetSiteInstanceForURL(url));
+  host->CreateRenderView(url, NULL);  // create a RenderViewHost with no view
+  background_hosts_.push_back(host);
 }
 
 SiteInstance* ExtensionsService::GetSiteInstanceForURL(const GURL& url) {
diff --git a/chrome/browser/extensions/extensions_service.h b/chrome/browser/extensions/extensions_service.h
index 2d075bc..d876f34 100644
--- a/chrome/browser/extensions/extensions_service.h
+++ b/chrome/browser/extensions/extensions_service.h
@@ -7,6 +7,7 @@
 
 #include <string>
 #include <vector>
+#include <list>
 
 #include "base/file_path.h"
 #include "base/message_loop.h"
@@ -17,6 +18,7 @@
 class Browser;
 class BrowsingInstance;
 class Extension;
+class ExtensionHost;
 class ExtensionView;
 class ExtensionsServiceBackend;
 class GURL;
@@ -82,6 +84,10 @@ class ExtensionsService : public ExtensionsServiceFrontendInterface {
                             const GURL& url,
                             Browser* browser);
 
+  // Creates a new UI-less extension instance.  Like CreateView, but not
+  // displayed anywhere.
+  void CreateBackgroundHost(Extension* extension, const GURL& url);
+
   // Returns the SiteInstance that the given URL belongs to.
   SiteInstance* GetSiteInstanceForURL(const GURL& url);
 
@@ -112,6 +118,10 @@ class ExtensionsService : public ExtensionsServiceFrontendInterface {
   // controls process grouping.
   scoped_refptr<BrowsingInstance> browsing_instance_;
 
+  // The list of running viewless background extensions.
+  typedef std::list<ExtensionHost*> ExtensionHostList;
+  ExtensionHostList background_hosts_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionsService);
 };
 
diff --git a/chrome/browser/extensions/extensions_service_unittest.cc b/chrome/browser/extensions/extensions_service_unittest.cc
index 685f914..b4a81c5 100644
--- a/chrome/browser/extensions/extensions_service_unittest.cc
+++ b/chrome/browser/extensions/extensions_service_unittest.cc
@@ -184,6 +184,7 @@ TEST_F(ExtensionsServiceTest, LoadAllExtensionsFromDirectorySuccess) {
             scripts[0].js_scripts()[0].path().value());
   EXPECT_EQ(extension->path().AppendASCII("script2.js").value(),
             scripts[0].js_scripts()[1].path().value());
+  EXPECT_TRUE(extension->plugins_dir().empty());
   EXPECT_EQ(1u, scripts[1].url_patterns().size());
   EXPECT_EQ("http://*.news.com/*", scripts[1].url_patterns()[0].GetAsString());
   EXPECT_EQ(extension->path().AppendASCII("js_files").AppendASCII("script3.js")
@@ -204,6 +205,8 @@ TEST_F(ExtensionsServiceTest, LoadAllExtensionsFromDirectorySuccess) {
             frontend->extensions()->at(1)->description());
   EXPECT_EQ(frontend->extensions()->at(1)->path().AppendASCII("npapi").value(),
             frontend->extensions()->at(1)->plugins_dir().value());
+  EXPECT_EQ(frontend->extensions()->at(1)->GetResourceURL("background.html"),
+            frontend->extensions()->at(1)->background_url());
   ASSERT_EQ(0u, frontend->extensions()->at(1)->content_scripts().size());
 
   EXPECT_EQ(std::string("20123456789abcdef0123456789abcdef0123456"),
diff --git a/chrome/browser/renderer_host/render_view_host.cc b/chrome/browser/renderer_host/render_view_host.cc
index d778250..3646358 100644
--- a/chrome/browser/renderer_host/render_view_host.cc
+++ b/chrome/browser/renderer_host/render_view_host.cc
@@ -160,14 +160,12 @@ bool RenderViewHost::CreateRenderView() {
       "Couldn't duplicate the modal dialog handle for the renderer.";
 #endif
 
-  DCHECK(view());
-
   ModalDialogEvent modal_dialog_event;
 #if defined(OS_WIN)
   modal_dialog_event.event = modal_dialog_event_handle;
 #endif
 
-  Send(new ViewMsg_New(gfx::IdFromNativeView(view()->GetPluginNativeView()),
+  Send(new ViewMsg_New(GetPluginNativeViewId(),
                        modal_dialog_event,
                        delegate_->GetWebkitPrefs(),
                        routing_id()));
diff --git a/chrome/browser/renderer_host/render_widget_host.cc b/chrome/browser/renderer_host/render_widget_host.cc
index 9e07de7..7a2122a 100644
--- a/chrome/browser/renderer_host/render_widget_host.cc
+++ b/chrome/browser/renderer_host/render_widget_host.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/renderer_host/render_widget_host.h"
 
-#include "base/gfx/native_widget_types.h"
 #include "base/histogram.h"
 #include "base/message_loop.h"
 #include "base/keyboard_codes.h"
@@ -79,15 +78,19 @@ RenderWidgetHost::~RenderWidgetHost() {
   process_->Release(routing_id_);
 }
 
+gfx::NativeViewId RenderWidgetHost::GetPluginNativeViewId() {
+  if (view_)
+    return gfx::IdFromNativeView(view_->GetPluginNativeView());
+  return NULL;
+}
+
 void RenderWidgetHost::Init() {
   DCHECK(process_->channel());
 
   renderer_initialized_ = true;
 
   // Send the ack along with the information on placement.
-  gfx::NativeView plugin_view = view_->GetPluginNativeView();
-  Send(new ViewMsg_CreatingNew_ACK(routing_id_,
-                                   gfx::IdFromNativeView(plugin_view)));
+  Send(new ViewMsg_CreatingNew_ACK(routing_id_, GetPluginNativeViewId()));
   WasResized();
 }
 
@@ -459,7 +462,8 @@ void RenderWidgetHost::OnMsgClose() {
 
 void RenderWidgetHost::OnMsgRequestMove(const gfx::Rect& pos) {
   // Note that we ignore the position.
-  view_->SetSize(pos.size());
+  if (view_)
+    view_->SetSize(pos.size());
 }
 
 void RenderWidgetHost::OnMsgPaintRect(
diff --git a/chrome/browser/renderer_host/render_widget_host.h b/chrome/browser/renderer_host/render_widget_host.h
index 0e93a84..861152a 100644
--- a/chrome/browser/renderer_host/render_widget_host.h
+++ b/chrome/browser/renderer_host/render_widget_host.h
@@ -8,6 +8,7 @@
 #include <queue>
 #include <vector>
 
+#include "base/gfx/native_widget_types.h"
 #include "base/gfx/size.h"
 #include "base/scoped_ptr.h"
 #include "base/timer.h"
@@ -267,6 +268,9 @@ class RenderWidgetHost : public IPC::Channel::Listener {
   // consistent if a new renderer is created.
   void RendererExited();
 
+  // Retrieves the native view used to contain plugins.
+  gfx::NativeViewId GetPluginNativeViewId();
+
   // Called when we an InputEvent was not processed by the renderer. This is
   // overridden by RenderView to send upwards to its delegate.
   virtual void UnhandledKeyboardEvent(const NativeWebKeyboardEvent& event) {}
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index 7820ae4..95bffd2 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -684,6 +684,8 @@
         'browser/extensions/extension_function.h',
         'browser/extensions/extension_function_dispatcher.cc',
         'browser/extensions/extension_function_dispatcher.h',
+        'browser/extensions/extension_host.cc',
+        'browser/extensions/extension_host.h',
         'browser/extensions/extension_message_service.cc',
         'browser/extensions/extension_message_service.h',
         'browser/extensions/extension_browser_event_router.cc',
diff --git a/chrome/common/temp_scaffolding_stubs.h b/chrome/common/temp_scaffolding_stubs.h
index c8d77fb..1b49f76 100644
--- a/chrome/common/temp_scaffolding_stubs.h
+++ b/chrome/common/temp_scaffolding_stubs.h
@@ -39,6 +39,7 @@ struct ViewHostMsg_DidPrintPage_Params;
 
 namespace gfx {
 class Rect;
+class Widget;
 }
 
 namespace IPC {
@@ -478,26 +479,38 @@ class BaseDragSource {
 //---------------------------------------------------------------------------
 // These stubs are for extensions
 
-class HWNDHtmlView {
+namespace views {
+class HWNDView {
  public:
-  HWNDHtmlView(const GURL& content_url, RenderViewHostDelegate* delegate,
-               bool allow_dom_ui_bindings, SiteInstance* instance) {
-    NOTIMPLEMENTED();
-  }
-  virtual ~HWNDHtmlView() {}
-
+  int width() { NOTIMPLEMENTED(); return 0; }
   int height() { NOTIMPLEMENTED(); return 0; }
-  RenderViewHost* render_view_host() { NOTIMPLEMENTED(); return NULL; }
   void InitHidden() { NOTIMPLEMENTED(); }
   void set_preferred_size(const gfx::Size& size) { NOTIMPLEMENTED(); }
   virtual void SetBackground(const SkBitmap&) { NOTIMPLEMENTED(); }
   virtual void SetVisible(bool flag) { NOTIMPLEMENTED(); }
   void SizeToPreferredSize() { NOTIMPLEMENTED(); }
-  HWNDHtmlView* GetParent() const { NOTIMPLEMENTED(); return NULL; }
   bool IsVisible() const { NOTIMPLEMENTED(); return false; }
   void Layout() { NOTIMPLEMENTED(); }
   void SchedulePaint() { NOTIMPLEMENTED(); }
+  HWNDView* GetParent() const { NOTIMPLEMENTED(); return NULL; }
+
+  gfx::NativeWindow GetHWND() { NOTIMPLEMENTED(); return 0; }
+  void Detach() { NOTIMPLEMENTED(); }
+  gfx::Widget* GetWidget() { NOTIMPLEMENTED(); return NULL; }
+};
+}  // namespace views
+
+class HWNDHtmlView : public views::HWNDView {
+ public:
+  HWNDHtmlView(const GURL& content_url, RenderViewHostDelegate* delegate,
+               bool allow_dom_ui_bindings, SiteInstance* instance) {
+    NOTIMPLEMENTED();
+  }
+  virtual ~HWNDHtmlView() {}
+
+  RenderViewHost* render_view_host() { NOTIMPLEMENTED(); return NULL; }
   SiteInstance* site_instance() { NOTIMPLEMENTED(); return NULL; }
 };
 
+
 #endif  // CHROME_COMMON_TEMP_SCAFFOLDING_STUBS_H_
diff --git a/chrome/test/data/extensions/good/extension2/2/background.html b/chrome/test/data/extensions/good/extension2/2/background.html
new file mode 100644
index 0000000..741876f
--- /dev/null
+++ b/chrome/test/data/extensions/good/extension2/2/background.html
@@ -0,0 +1 @@
+Dummy file.
diff --git a/chrome/test/data/extensions/good/extension2/2/manifest.json b/chrome/test/data/extensions/good/extension2/2/manifest.json
index 5e148f3..ba13bb7 100644
--- a/chrome/test/data/extensions/good/extension2/2/manifest.json
+++ b/chrome/test/data/extensions/good/extension2/2/manifest.json
@@ -2,5 +2,6 @@
   "id": "10123456789ABCDEF0123456789ABCDEF0123456",
   "version": "1.0.0.0",
   "name": "My extension 2",
-  "plugins_dir": "npapi"
+  "plugins_dir": "npapi",
+  "background": "background.html"
 }