Extract UI dependencies from ExtensionHost, part 2

Reduce ExtensionHost dependence on Browser by moving to ExtensionViewHost:
* Infobar CSS insertion
* "Associated web contents", which is only used for dialogs and infobars

This is part of the AppShell extensions refactor project.

BUG=321341
TEST=browser_tests, manual testing of extension with infobar
R=yoz@chromium.org

Review URL: https://codereview.chromium.org/89833002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237582 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 98 insertions, 75 deletions

diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 41a0440..ae306d4 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -50,12 +50,7 @@
 #include "extensions/common/extension_urls.h"
 #include "extensions/common/feature_switch.h"
 #include "extensions/common/manifest_handlers/background_info.h"
-#include "grit/browser_resources.h"
-#include "grit/chromium_strings.h"
-#include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
-#include "ui/base/resource/resource_bundle.h"
-#include "ui/events/keycodes/keyboard_codes.h"
 
 #if !defined(OS_ANDROID)
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
@@ -144,8 +139,7 @@ ExtensionHost::ExtensionHost(const Extension* extension,
       document_element_available_(false),
       initial_url_(url),
       extension_function_dispatcher_(profile_, this),
-      extension_host_type_(host_type),
-      associated_web_contents_(NULL) {
+      extension_host_type_(host_type) {
   // Not used for panels, see PanelHost.
   DCHECK(host_type == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE ||
          host_type == VIEW_TYPE_EXTENSION_DIALOG ||
@@ -181,29 +175,6 @@ ExtensionHost::~ExtensionHost() {
   ProcessCreationQueue::GetInstance()->Remove(this);
 }
 
-WebContents* ExtensionHost::GetAssociatedWebContents() const {
-  return associated_web_contents_;
-}
-
-WebContents* ExtensionHost::GetVisibleWebContents() const {
-  if (associated_web_contents_)
-    return associated_web_contents_;
-  if (extension_host_type_ == VIEW_TYPE_EXTENSION_POPUP)
-    return host_contents_.get();
-  return NULL;
-}
-
-// TODO(jamescook): Move this to ExtensionViewHost, as it is only used by
-// dialogs and infobars.
-void ExtensionHost::SetAssociatedWebContents(
-    content::WebContents* web_contents) {
-  associated_web_contents_ = web_contents;
-  if (web_contents) {
-    registrar_.Add(this, content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
-                   content::Source<WebContents>(associated_web_contents_));
-  }
-}
-
 content::RenderProcessHost* ExtensionHost::render_process_host() const {
   return render_view_host()->GetProcess();
 }
@@ -335,12 +306,6 @@ void ExtensionHost::Observe(int type,
         extension_ = NULL;
       }
       break;
-    case content::NOTIFICATION_WEB_CONTENTS_DESTROYED:
-      if (content::Source<WebContents>(source).ptr() ==
-          associated_web_contents_) {
-        associated_web_contents_ = NULL;
-      }
-      break;
     default:
       NOTREACHED() << "Unexpected notification sent.";
       break;
@@ -372,17 +337,6 @@ void ExtensionHost::RenderProcessGone(base::TerminationStatus status) {
       content::Details<ExtensionHost>(this));
 }
 
-// TODO(jamescook): Move to ExtensionViewHost, which handles infobars.
-void ExtensionHost::InsertInfobarCSS() {
-  DCHECK(!IsBackgroundPage());
-
-  static const base::StringPiece css(
-      ResourceBundle::GetSharedInstance().GetRawDataResource(
-      IDR_EXTENSIONS_INFOBAR_CSS));
-
-  render_view_host()->InsertCSS(string16(), css.as_string());
-}
-
 void ExtensionHost::DidStopLoading(content::RenderViewHost* render_view_host) {
   bool notify = !did_stop_loading_;
   did_stop_loading_ = true;
@@ -426,20 +380,14 @@ void ExtensionHost::DocumentAvailableInMainFrame() {
   // bail. No need for the redundant setup. http://crbug.com/31170
   if (document_element_available_)
     return;
-
   document_element_available_ = true;
-  if (IsBackgroundPage()) {
-    ExtensionSystem::Get(profile_)->extension_service()->
-        SetBackgroundPageReady(extension_);
-  } else {
-    switch (extension_host_type_) {
-      case VIEW_TYPE_EXTENSION_INFOBAR:
-        InsertInfobarCSS();
-        break;
-      default:
-        break;  // No style sheet for other types, at the moment.
-    }
-  }
+  OnDocumentAvailable();
+}
+
+void ExtensionHost::OnDocumentAvailable() {
+  DCHECK(extension_host_type_ == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
+  ExtensionSystem::Get(profile_)->extension_service()->
+      SetBackgroundPageReady(extension_);
 }
 
 void ExtensionHost::CloseContents(WebContents* contents) {
@@ -503,8 +451,9 @@ void ExtensionHost::OnDetailedConsoleMessageAdded(
     int32 severity_level) {
   if (IsSourceFromAnExtension(source)) {
     GURL context_url;
-    if (associated_web_contents_)
-      context_url = associated_web_contents_->GetLastCommittedURL();
+    WebContents* associated_contents = GetAssociatedWebContents();
+    if (associated_contents)
+      context_url = associated_contents->GetLastCommittedURL();
     else if (host_contents_.get())
       context_url = host_contents_->GetLastCommittedURL();
 
diff --git a/chrome/browser/extensions/extension_host.h b/chrome/browser/extensions/extension_host.h
index c2abeef..50a4b97 100644
--- a/chrome/browser/extensions/extension_host.h
+++ b/chrome/browser/extensions/extension_host.h
@@ -79,11 +79,6 @@ class ExtensionHost : public content::WebContentsDelegate,
   ViewType extension_host_type() const { return extension_host_type_; }
   const GURL& GetURL() const;
 
-  // ExtensionFunctionDispatcher::Delegate
-  virtual content::WebContents* GetAssociatedWebContents() const OVERRIDE;
-  virtual content::WebContents* GetVisibleWebContents() const OVERRIDE;
-  void SetAssociatedWebContents(content::WebContents* web_contents);
-
   // Returns true if the render view is initialized and didn't crash.
   bool IsRenderViewLive() const;
 
@@ -92,9 +87,6 @@ class ExtensionHost : public content::WebContentsDelegate,
   // (can be NULL). This happens delayed to avoid locking the UI.
   void CreateRenderViewSoon();
 
-  // Insert a default style sheet for Extension Infobars.
-  void InsertInfobarCSS();
-
   // Notifications from the JavaScriptDialogManager when a dialog is being
   // opened/closed.
   void WillRunJavaScriptDialog();
@@ -138,9 +130,13 @@ class ExtensionHost : public content::WebContentsDelegate,
                        const content::NotificationDetails& details) OVERRIDE;
 
  protected:
-  // Called before the EXTENSION_HOST_DID_STOP_LOADING notification is sent.
+  // Called after the extension page finishes loading but before the
+  // EXTENSION_HOST_DID_STOP_LOADING notification is sent.
   virtual void OnDidStopLoading();
 
+  // Called once when the document first becomes available.
+  virtual void OnDocumentAvailable();
+
   // Returns true if we're hosting a background page.
   virtual bool IsBackgroundPage() const;
 
@@ -221,9 +217,6 @@ class ExtensionHost : public content::WebContentsDelegate,
   // The type of view being hosted.
   ViewType extension_host_type_;
 
-  // The relevant WebContents associated with this ExtensionHost, if any.
-  content::WebContents* associated_web_contents_;
-
   // Used to measure how long it's been since the host was created.
   base::ElapsedTimer since_created_;
 
diff --git a/chrome/browser/extensions/extension_view_host.cc b/chrome/browser/extensions/extension_view_host.cc
index 2e2cd70..0623177 100644
--- a/chrome/browser/extensions/extension_view_host.cc
+++ b/chrome/browser/extensions/extension_view_host.cc
@@ -4,24 +4,51 @@
 
 #include "chrome/browser/extensions/extension_view_host.h"
 
+#include "base/strings/string_piece.h"
 #include "chrome/browser/extensions/window_controller.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "content/public/browser/render_view_host.h"
+#include "grit/browser_resources.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/events/keycodes/keyboard_codes.h"
 
 using content::NativeWebKeyboardEvent;
 using content::OpenURLParams;
 using content::RenderViewHost;
 using content::WebContents;
+using content::WebContentsObserver;
 
 namespace extensions {
 
+// Notifies an ExtensionViewHost when a WebContents is destroyed.
+class ExtensionViewHost::AssociatedWebContentsObserver
+    : public WebContentsObserver {
+ public:
+  AssociatedWebContentsObserver(ExtensionViewHost* host,
+                                WebContents* web_contents)
+      : WebContentsObserver(web_contents), host_(host) {}
+  virtual ~AssociatedWebContentsObserver() {}
+
+  // content::WebContentsObserver:
+  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
+    // Deleting |this| from here is safe.
+    host_->SetAssociatedWebContents(NULL);
+  }
+
+ private:
+  ExtensionViewHost* host_;
+
+  DISALLOW_COPY_AND_ASSIGN(AssociatedWebContentsObserver);
+};
+
 ExtensionViewHost::ExtensionViewHost(
     const Extension* extension,
     content::SiteInstance* site_instance,
     const GURL& url,
     ViewType host_type)
-    : ExtensionHost(extension, site_instance, url, host_type) {
+    : ExtensionHost(extension, site_instance, url, host_type),
+      associated_web_contents_(NULL) {
   // Not used for panels, see PanelHost.
   DCHECK(host_type == VIEW_TYPE_EXTENSION_DIALOG ||
          host_type == VIEW_TYPE_EXTENSION_INFOBAR ||
@@ -48,6 +75,17 @@ void ExtensionViewHost::CreateView(Browser* browser) {
 #endif
 }
 
+void ExtensionViewHost::SetAssociatedWebContents(WebContents* web_contents) {
+  associated_web_contents_ = web_contents;
+  if (associated_web_contents_) {
+    // Observe the new WebContents for deletion.
+    associated_web_contents_observer_.reset(
+        new AssociatedWebContentsObserver(this, associated_web_contents_));
+  } else {
+    associated_web_contents_observer_.reset();
+  }
+}
+
 // ExtensionHost overrides:
 
 void ExtensionViewHost::UnhandledKeyboardEvent(
@@ -75,6 +113,13 @@ void ExtensionViewHost::OnDidStopLoading() {
 #endif
 }
 
+void ExtensionViewHost::OnDocumentAvailable() {
+  if (extension_host_type() == VIEW_TYPE_EXTENSION_INFOBAR) {
+    // No style sheet for other types, at the moment.
+    InsertInfobarCSS();
+  }
+}
+
 bool ExtensionViewHost::IsBackgroundPage() const {
   DCHECK(view_);
   return false;
@@ -168,4 +213,24 @@ WindowController* ExtensionViewHost::GetExtensionWindowController() const {
                           : NULL;
 }
 
+WebContents* ExtensionViewHost::GetAssociatedWebContents() const {
+  return associated_web_contents_;
+}
+
+WebContents* ExtensionViewHost::GetVisibleWebContents() const {
+  if (associated_web_contents_)
+    return associated_web_contents_;
+  if (extension_host_type() == VIEW_TYPE_EXTENSION_POPUP)
+    return host_contents();
+  return NULL;
+}
+
+void ExtensionViewHost::InsertInfobarCSS() {
+  static const base::StringPiece css(
+      ResourceBundle::GetSharedInstance().GetRawDataResource(
+      IDR_EXTENSIONS_INFOBAR_CSS));
+
+  render_view_host()->InsertCSS(string16(), css.as_string());
+}
+
 }  // namespace extensions
diff --git a/chrome/browser/extensions/extension_view_host.h b/chrome/browser/extensions/extension_view_host.h
index afb548d..aa92531 100644
--- a/chrome/browser/extensions/extension_view_host.h
+++ b/chrome/browser/extensions/extension_view_host.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_VIEW_HOST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_VIEW_HOST_H_
 
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/extensions/extension_host.h"
 
 #if defined(TOOLKIT_VIEWS)
@@ -57,6 +58,8 @@ class ExtensionViewHost : public ExtensionHost {
   // instantiate Browser objects.
   void CreateView(Browser* browser);
 
+  void SetAssociatedWebContents(content::WebContents* web_contents);
+
   // Handles keyboard events that were not handled by HandleKeyboardEvent().
   // Platform specific implementation may override this method to handle the
   // event in platform specific way.
@@ -66,6 +69,7 @@ class ExtensionViewHost : public ExtensionHost {
 
   // ExtensionHost
   virtual void OnDidStopLoading() OVERRIDE;
+  virtual void OnDocumentAvailable() OVERRIDE;
   virtual bool IsBackgroundPage() const OVERRIDE;
 
   // content::WebContentsDelegate
@@ -93,11 +97,23 @@ class ExtensionViewHost : public ExtensionHost {
 
   // ExtensionFunctionDispatcher::Delegate
   virtual WindowController* GetExtensionWindowController() const OVERRIDE;
+  virtual content::WebContents* GetAssociatedWebContents() const OVERRIDE;
+  virtual content::WebContents* GetVisibleWebContents() const OVERRIDE;
 
  private:
+  // Insert a default style sheet for Extension Infobars.
+  void InsertInfobarCSS();
+
   // Optional view that shows the rendered content in the UI.
   scoped_ptr<PlatformExtensionView> view_;
 
+  // The relevant WebContents associated with this ExtensionViewHost, if any.
+  content::WebContents* associated_web_contents_;
+
+  // Observer to detect when the associated web contents is destroyed.
+  class AssociatedWebContentsObserver;
+  scoped_ptr<AssociatedWebContentsObserver> associated_web_contents_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionViewHost);
 };