Move ZoomController out of ChromeWebViewGuestDelegate.

This CL moves the ZoomController code for WebView out of
ChromeWebViewGuestDelegate and into GuestViewBase and WebViewGuest. This
will allow non-chrome builds to access the WebView zoom api.

BUG=none

Review URL: https://codereview.chromium.org/787813004

Cr-Commit-Position: refs/heads/master@{#308094}

chrome/browser/guest_view/web_view/chrome_web_view_guest_delegate.cc

@@ -12,8 +12,6 @@
 #include "chrome/common/chrome_version_info.h"
 #include "components/pdf/browser/pdf_web_contents_helper.h"
 #include "components/renderer_context_menu/context_menu_delegate.h"
-#include "components/ui/zoom/zoom_controller.h"
-#include "content/public/common/page_zoom.h"
 #include "extensions/browser/api/web_request/web_request_api.h"
 #include "extensions/browser/guest_view/web_view/web_view_constants.h"
 
@@ -28,13 +26,10 @@
 
 namespace extensions {
 
-using ui_zoom::ZoomController;
-
 ChromeWebViewGuestDelegate::ChromeWebViewGuestDelegate(
     WebViewGuest* web_view_guest)
     : pending_context_menu_request_id_(0),
       chromevox_injected_(false),
-      current_zoom_factor_(1.0),
       web_view_guest_(web_view_guest),
       weak_ptr_factory_(this) {
 }
@@ -42,10 +37,6 @@ ChromeWebViewGuestDelegate::ChromeWebViewGuestDelegate(
 ChromeWebViewGuestDelegate::~ChromeWebViewGuestDelegate() {
 }
 
-double ChromeWebViewGuestDelegate::GetZoom() {
-  return current_zoom_factor_;
-}
-
 bool ChromeWebViewGuestDelegate::HandleContextMenu(
     const content::ContextMenuParams& params) {
   ContextMenuDelegate* menu_delegate =
@@ -70,14 +61,6 @@ bool ChromeWebViewGuestDelegate::HandleContextMenu(
 // extension module in the future.
 void ChromeWebViewGuestDelegate::OnAttachWebViewHelpers(
     content::WebContents* contents) {
-  // Create a zoom controller for the guest contents give it access to
-  // GetZoomLevel() and and SetZoomLevel() in WebViewGuest.
-  // TODO(wjmaclean) This currently uses the same HostZoomMap as the browser
-  // context, but we eventually want to isolate the guest contents from zoom
-  // changes outside the guest (e.g. in the main browser), so we should
-  // create a separate HostZoomMap for the guest.
-  ZoomController::CreateForWebContents(contents);
-
   FaviconTabHelper::CreateForWebContents(contents);
   ChromeExtensionWebContentsObserver::CreateForWebContents(contents);
 #if defined(ENABLE_PRINTING)
@@ -94,28 +77,8 @@ void ChromeWebViewGuestDelegate::OnAttachWebViewHelpers(
           new ChromePDFWebContentsHelperClient()));
 }
 
-void ChromeWebViewGuestDelegate::OnDidAttachToEmbedder() {
-  // TODO(fsamuel): This code should be implemented in GuestViewBase once the
-  // ZoomController moves to the extensions module.
-  ZoomController* zoom_controller = ZoomController::FromWebContents(
-      web_view_guest()->embedder_web_contents());
-  if (!zoom_controller)
-    return;
-  // Listen to the embedder's zoom changes.
-  zoom_controller->AddObserver(this);
-  // Set the guest's initial zoom level to be equal to the embedder's.
-  ZoomController::FromWebContents(guest_web_contents())->
-      SetZoomLevel(zoom_controller->GetZoomLevel());
-}
-
 void ChromeWebViewGuestDelegate::OnDidCommitProvisionalLoadForFrame(
     bool is_main_frame) {
-  // Update the current zoom factor for the new page.
-  ZoomController* zoom_controller =
-      ZoomController::FromWebContents(guest_web_contents());
-  DCHECK(zoom_controller);
-  current_zoom_factor_ =
-      content::ZoomLevelToZoomFactor(zoom_controller->GetZoomLevel());
   if (is_main_frame)
     chromevox_injected_ = false;
 }
@@ -137,18 +100,6 @@ void ChromeWebViewGuestDelegate::OnDocumentLoadedInFrame(
     InjectChromeVoxIfNeeded(render_frame_host->GetRenderViewHost());
 }
 
-void ChromeWebViewGuestDelegate::OnEmbedderWillBeDestroyed() {
-  content::WebContents* embedder_web_contents =
-      web_view_guest()->embedder_web_contents();
-  if (!embedder_web_contents)
-    return;
-
-  ZoomController* zoom_controller =
-      ZoomController::FromWebContents(embedder_web_contents);
-  if (zoom_controller)
-    zoom_controller->RemoveObserver(this);
-}
-
 void ChromeWebViewGuestDelegate::OnGuestDestroyed() {
   // Clean up custom context menu items for this guest.
   MenuManager* menu_manager = MenuManager::Get(
@@ -174,21 +125,6 @@ scoped_ptr<base::ListValue> ChromeWebViewGuestDelegate::MenuModelToValue(
   return items.Pass();
 }
 
-void ChromeWebViewGuestDelegate::OnSetZoom(double zoom_factor) {
-  ZoomController* zoom_controller =
-      ZoomController::FromWebContents(guest_web_contents());
-  DCHECK(zoom_controller);
-  double zoom_level = content::ZoomFactorToZoomLevel(zoom_factor);
-  zoom_controller->SetZoomLevel(zoom_level);
-
-  scoped_ptr<base::DictionaryValue> args(new base::DictionaryValue());
-  args->SetDouble(webview::kOldZoomFactor, current_zoom_factor_);
-  args->SetDouble(webview::kNewZoomFactor, zoom_factor);
-  web_view_guest()->DispatchEventToEmbedder(
-      new GuestViewBase::Event(webview::kEventZoomChange, args.Pass()));
-  current_zoom_factor_ = zoom_factor;
-}
-
 void ChromeWebViewGuestDelegate::OnShowContextMenu(
     int request_id,
     const MenuItemVector* items) {
@@ -236,10 +172,4 @@ void ChromeWebViewGuestDelegate::OnAccessibilityStatusChanged(
 }
 #endif
 
-void ChromeWebViewGuestDelegate::OnZoomChanged(
-    const ZoomController::ZoomChangedEventData& data) {
-  ZoomController::FromWebContents(guest_web_contents())->
-      SetZoomLevel(data.new_zoom_level);
-}
-
 }  // namespace extensions

chrome/browser/guest_view/web_view/chrome_web_view_guest_delegate.h

@@ -6,7 +6,6 @@
 #define CHROME_BROWSER_GUEST_VIEW_WEB_VIEW_CHROME_WEB_VIEW_GUEST_DELEGATE_H_
 
 #include "chrome/browser/extensions/api/web_view/chrome_web_view_internal_api.h"
-#include "components/ui/zoom/zoom_observer.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest_delegate.h"
 
@@ -22,30 +21,21 @@ class SimpleMenuModel;
 
 namespace extensions {
 
-class ChromeWebViewGuestDelegate : public WebViewGuestDelegate,
-                                   public ui_zoom::ZoomObserver {
+class ChromeWebViewGuestDelegate : public WebViewGuestDelegate {
  public :
   explicit ChromeWebViewGuestDelegate(WebViewGuest* web_view_guest);
   ~ChromeWebViewGuestDelegate() override;
 
   // WebViewGuestDelegate implementation.
-  double GetZoom() override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
   void OnAttachWebViewHelpers(content::WebContents* contents) override;
-  void OnDidAttachToEmbedder() override;
   void OnDidCommitProvisionalLoadForFrame(bool is_main_frame) override;
   void OnDidInitialize() override;
   void OnDocumentLoadedInFrame(
       content::RenderFrameHost* render_frame_host) override;
-  void OnEmbedderWillBeDestroyed() override;
   void OnGuestDestroyed() override;
-  void OnSetZoom(double zoom_factor) override;
   void OnShowContextMenu(int request_id, const MenuItemVector* items) override;
 
-  // ZoomObserver implementation.
-  void OnZoomChanged(
-      const ui_zoom::ZoomController::ZoomChangedEventData& data) override;
-
   WebViewGuest* web_view_guest() const { return web_view_guest_; }
 
  private:
@@ -72,9 +62,6 @@ class ChromeWebViewGuestDelegate : public WebViewGuestDelegate,
   // Set to |true| if ChromeVox was already injected in main frame.
   bool chromevox_injected_;
 
-  // Stores the current zoom factor.
-  double current_zoom_factor_;
-
   // Holds the RenderViewContextMenuBase that has been built but yet to be
   // shown. This is .reset() after ShowContextMenu().
   scoped_ptr<RenderViewContextMenuBase> pending_menu_;

extensions/browser/BUILD.gn

@@ -15,6 +15,7 @@ source_set("browser") {
     "//components/keyed_service/core",
     "//components/pref_registry",
     "//components/sessions:sessions_content",
+    "//components/ui/zoom:ui_zoom",
     "//components/web_cache/browser",
     "//components/web_modal",
     "//content/public/browser",

extensions/browser/api/web_view/web_view_internal_api.cc

@@ -213,7 +213,7 @@ bool WebViewInternalGetZoomFunction::RunAsyncSafe(WebViewGuest* guest) {
       webview::GetZoom::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
-  double zoom_factor = guest->GetZoom();
+  double zoom_factor = guest->zoom();
   SetResult(new base::FundamentalValue(zoom_factor));
   SendResponse(true);
   return true;

extensions/browser/guest_view/guest_view_base.cc

@@ -6,11 +6,13 @@
 
 #include "base/lazy_instance.h"
 #include "base/strings/utf_string_conversions.h"
+#include "components/ui/zoom/zoom_controller.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/page_zoom.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/browser/api/extensions_api_client.h"
 #include "extensions/browser/event_router.h"
@@ -102,7 +104,6 @@ class GuestViewBase::OwnerLifetimeObserver : public WebContentsObserver {
 
     destroyed_ = true;
     guest_->EmbedderWillBeDestroyed();
-    guest_->owner_web_contents_ = NULL;
     guest_->Destroy();
   }
 
@@ -146,6 +147,7 @@ GuestViewBase::GuestViewBase(content::BrowserContext* browser_context,
       is_being_destroyed_(false),
       auto_size_enabled_(false),
       is_full_page_plugin_(false),
+      observing_owners_zoom_controller_(false),
       weak_ptr_factory_(this) {
 }
 
@@ -209,6 +211,9 @@ void GuestViewBase::InitWithWebContents(
   GuestViewManager::FromBrowserContext(browser_context_)->
       AddGuest(guest_instance_id_, guest_web_contents);
 
+  // Create a ZoomController to allow the guest's contents to be zoomed.
+  ui_zoom::ZoomController::CreateForWebContents(guest_web_contents);
+
   // Give the derived class an opportunity to perform additional initialization.
   DidInitialize();
 }
@@ -309,6 +314,9 @@ bool GuestViewBase::IsDragAndDropEnabled() const {
 void GuestViewBase::DidAttach(int guest_proxy_routing_id) {
   opener_lifetime_observer_.reset();
 
+  // Any zoom events from the embedder should be relayed to the guest.
+  StartObservingOwnersZoomController();
+
   // Give the derived class an opportunity to perform some actions.
   DidAttachToEmbedder();
 
@@ -357,6 +365,12 @@ void GuestViewBase::Destroy() {
 
   is_being_destroyed_ = true;
 
+  // It is important to clear owner_web_contents_ after the call to
+  // StopObservingOwnersZoomControllerIfNecessary(), but before the rest of
+  // the statements in this function.
+  StopObservingOwnersZoomControllerIfNecessary();
+  owner_web_contents_ = NULL;
+
   DCHECK(web_contents());
 
   // Give the derived class an opportunity to perform some cleanup.
@@ -485,6 +499,17 @@ bool GuestViewBase::PreHandleGestureEvent(content::WebContents* source,
 GuestViewBase::~GuestViewBase() {
 }
 
+void GuestViewBase::OnZoomChanged(
+    const ui_zoom::ZoomController::ZoomChangedEventData& data) {
+  if (content::ZoomValuesEqual(data.old_zoom_level, data.new_zoom_level))
+    return;
+
+  // When the embedder's zoom level is changed, then we also update the
+  // guest's zoom level to match.
+  ui_zoom::ZoomController::FromWebContents(web_contents())
+      ->SetZoomLevel(data.new_zoom_level);
+}
+
 void GuestViewBase::DispatchEventToEmbedder(Event* event) {
   scoped_ptr<Event> event_ptr(event);
 
@@ -532,6 +557,33 @@ void GuestViewBase::CompleteInit(const std::string& owner_extension_id,
   callback.Run(guest_web_contents);
 }
 
+void GuestViewBase::StartObservingOwnersZoomController() {
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(embedder_web_contents());
+  if (!zoom_controller)
+    return;
+
+  // Listen to the embedder's zoom changes.
+  zoom_controller->AddObserver(this);
+  observing_owners_zoom_controller_ = true;
+  // Set the guest's initial zoom level to be equal to the embedder's.
+  ui_zoom::ZoomController::FromWebContents(web_contents())
+      ->SetZoomLevel(zoom_controller->GetZoomLevel());
+}
+
+void GuestViewBase::StopObservingOwnersZoomControllerIfNecessary() {
+  // We use owner_web_contents_ below and not embedder_web_contents() since
+  // we may have been detached by this point.
+  DCHECK(!observing_owners_zoom_controller_ || owner_web_contents_);
+  if (!owner_web_contents_ || !observing_owners_zoom_controller_)
+    return;
+
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(owner_web_contents_);
+  zoom_controller->RemoveObserver(this);
+  observing_owners_zoom_controller_ = false;
+}
+
 // static
 void GuestViewBase::RegisterGuestViewTypes() {
   AppViewGuest::Register();

extensions/browser/guest_view/guest_view_base.h

@@ -9,6 +9,7 @@
 
 #include "base/memory/weak_ptr.h"
 #include "base/values.h"
+#include "components/ui/zoom/zoom_observer.h"
 #include "content/public/browser/browser_plugin_guest_delegate.h"
 #include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/web_contents.h"
@@ -28,7 +29,8 @@ namespace extensions {
 // it is attached to a container within the owner's WebContents.
 class GuestViewBase : public content::BrowserPluginGuestDelegate,
                       public content::WebContentsDelegate,
-                      public content::WebContentsObserver {
+                      public content::WebContentsObserver,
+                      public ui_zoom::ZoomObserver {
  public:
   class Event {
    public:
@@ -246,6 +248,10 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
                   int browser_plugin_instance_id,
                   bool is_full_page_plugin) final;
 
+  // ui_zoom::ZoomObserver implementation.
+  void OnZoomChanged(
+      const ui_zoom::ZoomController::ZoomChangedEventData& data) override;
+
   // Dispatches an event |event_name| to the embedder with the |event| fields.
   void DispatchEventToEmbedder(Event* event);
 
@@ -267,6 +273,9 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
                     const WebContentsCreatedCallback& callback,
                     content::WebContents* guest_web_contents);
 
+  void StartObservingOwnersZoomController();
+  void StopObservingOwnersZoomControllerIfNecessary();
+
   static void RegisterGuestViewTypes();
 
   // WebContentsObserver implementation.
@@ -352,6 +361,8 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
   // Whether the guest view is inside a plugin document.
   bool is_full_page_plugin_;
 
+  bool observing_owners_zoom_controller_;
+
   // This is used to ensure pending tasks will not fire after this object is
   // destroyed.
   base::WeakPtrFactory<GuestViewBase> weak_ptr_factory_;

extensions/browser/guest_view/web_view/web_view_guest.cc

@@ -337,9 +337,6 @@ void WebViewGuest::DidAttachToEmbedder() {
   // We need to set the background opaque flag after navigation to ensure that
   // there is a RenderWidgetHostView available.
   SetAllowTransparency(allow_transparency);
-
-  if (web_view_guest_delegate_)
-    web_view_guest_delegate_->OnDidAttachToEmbedder();
 }
 
 void WebViewGuest::DidInitialize() {
@@ -372,9 +369,6 @@ void WebViewGuest::DidStopLoading() {
 }
 
 void WebViewGuest::EmbedderWillBeDestroyed() {
-  if (web_view_guest_delegate_)
-    web_view_guest_delegate_->OnEmbedderWillBeDestroyed();
-
   // Clean up rules registries for the webview.
   RulesRegistryService::Get(browser_context())
       ->RemoveRulesRegistriesByID(rules_registry_id_);
@@ -620,12 +614,6 @@ void WebViewGuest::Observe(int type,
   }
 }
 
-double WebViewGuest::GetZoom() {
-  if (!web_view_guest_delegate_)
-    return 1.0;
-  return web_view_guest_delegate_->GetZoom();
-}
-
 void WebViewGuest::StartFinding(
     const base::string16& search_text,
     const blink::WebFindOptions& options,
@@ -712,6 +700,7 @@ WebViewGuest::WebViewGuest(content::BrowserContext* browser_context,
       is_overriding_user_agent_(false),
       guest_opaque_(true),
       javascript_dialog_helper_(this),
+      current_zoom_factor_(1.0),
       weak_ptr_factory_(this) {
   web_view_guest_delegate_.reset(
       ExtensionsAPIClient::Get()->CreateWebViewGuestDelegate(this));
@@ -745,6 +734,14 @@ void WebViewGuest::DidCommitProvisionalLoadForFrame(
       new GuestViewBase::Event(webview::kEventLoadCommit, args.Pass()));
 
   find_helper_.CancelAllFindSessions();
+
+  // Update the current zoom factor for the new page.
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(web_contents());
+  DCHECK(zoom_controller);
+  current_zoom_factor_ =
+      content::ZoomLevelToZoomFactor(zoom_controller->GetZoomLevel());
+
   if (web_view_guest_delegate_) {
     web_view_guest_delegate_->OnDidCommitProvisionalLoadForFrame(
         !render_frame_host->GetParent());
@@ -1067,8 +1064,18 @@ void WebViewGuest::SetName(const std::string& name) {
 }
 
 void WebViewGuest::SetZoom(double zoom_factor) {
-  if (web_view_guest_delegate_)
-    web_view_guest_delegate_->OnSetZoom(zoom_factor);
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(web_contents());
+  DCHECK(zoom_controller);
+  double zoom_level = content::ZoomFactorToZoomLevel(zoom_factor);
+  zoom_controller->SetZoomLevel(zoom_level);
+
+  scoped_ptr<base::DictionaryValue> args(new base::DictionaryValue());
+  args->SetDouble(webview::kOldZoomFactor, current_zoom_factor_);
+  args->SetDouble(webview::kNewZoomFactor, zoom_factor);
+  DispatchEventToEmbedder(
+      new GuestViewBase::Event(webview::kEventZoomChange, args.Pass()));
+  current_zoom_factor_ = zoom_factor;
 }
 
 void WebViewGuest::SetAllowTransparency(bool allow) {

extensions/browser/guest_view/web_view/web_view_guest.h

@@ -174,7 +174,7 @@ class WebViewGuest : public GuestView<WebViewGuest>,
                const content::NotificationDetails& details) override;
 
   // Returns the current zoom factor.
-  double GetZoom();
+  double zoom() const { return current_zoom_factor_; }
 
   // Begin or continue a find request.
   void StartFinding(const base::string16& search_text,
@@ -368,6 +368,9 @@ class WebViewGuest : public GuestView<WebViewGuest>,
   typedef std::map<WebViewGuest*, NewWindowInfo> PendingWindowMap;
   PendingWindowMap pending_new_windows_;
 
+  // Stores the current zoom factor.
+  double current_zoom_factor_;
+
   // This is used to ensure pending tasks will not fire after this object is
   // destroyed.
   base::WeakPtrFactory<WebViewGuest> weak_ptr_factory_;

extensions/browser/guest_view/web_view/web_view_guest_delegate.h

@@ -31,19 +31,12 @@ class WebViewGuestDelegate {
   typedef std::vector<linked_ptr<api::web_view_internal::ContextMenuItem> >
       MenuItemVector;
 
-  // Returns the current zoom factor.
-  virtual double GetZoom() = 0;
-
   // Called when context menu operation was handled.
   virtual bool HandleContextMenu(const content::ContextMenuParams& params) = 0;
 
   // Called to attach helpers just after additional initialization is performed.
   virtual void OnAttachWebViewHelpers(content::WebContents* contents) = 0;
 
-  // Called after the guest has been attached to an embedder and suspended
-  // resource loads have been resumed.
-  virtual void OnDidAttachToEmbedder() = 0;
-
   // Called when the guest WebContents commits a provisional load in any frame.
   virtual void OnDidCommitProvisionalLoadForFrame(bool is_main_frame) = 0;
 
@@ -53,15 +46,9 @@ class WebViewGuestDelegate {
   virtual void OnDocumentLoadedInFrame(
       content::RenderFrameHost* render_frame_host) = 0;
 
-  // Called before the embedder is destroyed.
-  virtual void OnEmbedderWillBeDestroyed() = 0;
-
   // Called immediately after the guest WebContents has been destroyed.
   virtual void OnGuestDestroyed() = 0;
 
-  // Called when to set the zoom factor.
-  virtual void OnSetZoom(double zoom_factor) = 0;
-
   // Shows the context menu for the guest.
   // |items| acts as a filter. This restricts the current context's default
   // menu items to contain only the items from |items|.

extensions/extensions.gyp

@@ -294,6 +294,7 @@
         '../components/components.gyp:pref_registry',
         '../components/components.gyp:sessions_content',
         '../components/components.gyp:storage_monitor',
+        '../components/components.gyp:ui_zoom',
         '../components/components.gyp:web_cache_browser',
         '../components/components.gyp:web_modal',
         '../content/content.gyp:content_browser',