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..7f2e2cd81abf49df5f180217a2bc491dee6eff68 100644
--- a/extensions/browser/guest_view/guest_view_base.cc
+++ b/extensions/browser/guest_view/guest_view_base.cc
@@ -6,6 +6,7 @@
 
 #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"
@@ -209,6 +210,12 @@ void GuestViewBase::InitWithWebContents(
   GuestViewManager::FromBrowserContext(browser_context_)->
       AddGuest(guest_instance_id_, guest_web_contents);
 
+  // Create a zoom controller for the guest contents give it access to
+  // GetZoomLevel() and and SetZoomLevel() in WebViewGuest.

[Fady Samuel, 2014/12/09 20:09:46]

This comment is no longer correct as this code lives in GuestViewBase. I'd
simply remove it and add a brief comment about what functionality ZoomController
provides.

[wjmaclean, 2014/12/09 20:50:04]

Done.

+  // TODO(wjmaclean): Verify that |guest_web_contents| is the right value to
+  // pass here.

[Fady Samuel, 2014/12/09 20:09:46]

This looks right to me.

[wjmaclean, 2014/12/09 20:50:04]

Acknowledged.

+  ui_zoom::ZoomController::CreateForWebContents(guest_web_contents);
+
   // Give the derived class an opportunity to perform additional initialization.
   DidInitialize();
 }
@@ -298,6 +305,14 @@ bool GuestViewBase::IsGuest(WebContents* web_contents) {
   return !!GuestViewBase::FromWebContents(web_contents);
 }
 
+void GuestViewBase::EmbedderWillBeDestroyed() {
+  ui_zoom::ZoomController* zoom_controller =
+      ui_zoom::ZoomController::FromWebContents(embedder_web_contents());
+  if (!zoom_controller)
+    return;
+  zoom_controller->RemoveObserver(this);
+}
+
 bool GuestViewBase::IsAutoSizeSupported() const {
   return false;
 }
@@ -309,6 +324,17 @@ 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 +511,12 @@ bool GuestViewBase::PreHandleGestureEvent(content::WebContents* source,
 GuestViewBase::~GuestViewBase() {
 }
 
+void GuestViewBase::OnZoomChanged(
+    const ui_zoom::ZoomController::ZoomChangedEventData& data) {
+  ui_zoom::ZoomController::FromWebContents(web_contents())

[Fady Samuel, 2014/12/09 20:09:46]

It would be nice to add a comment here that updating the embedder's zoom level
updates the guest's zoom level.

[wjmaclean, 2014/12/09 20:50:04]

Done.

+      ->SetZoomLevel(data.new_zoom_level);
+}
+
 void GuestViewBase::DispatchEventToEmbedder(Event* event) {
   scoped_ptr<Event> event_ptr(event);