Move ZoomController out of ChromeWebViewGuestDelegate.

extensions/browser/guest_view/guest_view_base.cc

Index: extensions/browser/guest_view/guest_view_base.cc
diff --git a/extensions/browser/guest_view/guest_view_base.cc b/extensions/browser/guest_view/guest_view_base.cc
index 7936ee7db08e47c4d16e79ba514f9e6829d1a05c..7c224462271e56f29b1842c70e4cd2442954d74f 100644
--- a/extensions/browser/guest_view/guest_view_base.cc
+++ b/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"
@@ -100,7 +102,7 @@ class GuestViewBase::OwnerLifetimeObserver : public WebContentsObserver {
       return;
 
     destroyed_ = true;
-    guest_->EmbedderWillBeDestroyed();
+    guest_->OwnerWebContentsWillBeDestroyed();
     guest_->owner_web_contents_ = NULL;
     guest_->Destroy();
   }
@@ -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 +314,17 @@ 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.
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(embedder_web_contents());
+  if (zoom_controller) {
+    // 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.
+    ui_zoom::ZoomController::FromWebContents(web_contents())
+        ->SetZoomLevel(zoom_controller->GetZoomLevel());
+  }
+
   // Give the derived class an opportunity to perform some actions.
   DidAttachToEmbedder();
 
@@ -485,6 +501,17 @@ 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 +559,15 @@ void GuestViewBase::CompleteInit(const std::string& owner_extension_id,
   callback.Run(guest_web_contents);
 }
 
+void GuestViewBase::OwnerWebContentsWillBeDestroyed() {
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(embedder_web_contents());
+  if (zoom_controller)
+    zoom_controller->RemoveObserver(this);
+
+  EmbedderWillBeDestroyed();
+}
+
 // static
 void GuestViewBase::RegisterGuestViewTypes() {
   AppViewGuest::Register();