Revert of Add support for entering/exiting HTML fullscreen from OOPIFs.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index 3470a3c8a57ec4f10775df91ce0dedce882c0233..6020cd0112106ef4e40ee032aafeca7cf48860f8 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -1779,40 +1779,7 @@
   }
 }
 
-// TODO(alexmos): When the allowFullscreen flag is known in the browser
-// process, use it to double-check that fullscreen can be entered here.
 void RenderFrameHostImpl::OnToggleFullscreen(bool enter_fullscreen) {
-  // Entering fullscreen from a cross-process subframe also affects all
-  // renderers for ancestor frames, which will need to apply fullscreen CSS to
-  // appropriate ancestor <iframe> elements, fire fullscreenchange events, etc.
-  // Thus, walk through the ancestor chain of this frame and for each (parent,
-  // child) pair, send a message about the pending fullscreen change to the
-  // child's proxy in parent's SiteInstance. The renderer process will use this
-  // to find the <iframe> element in the parent frame that will need fullscreen
-  // styles. This is done at most once per SiteInstance: for example, with a
-  // A-B-A-B hierarchy, if the bottom frame goes fullscreen, this only needs to
-  // notify its parent, and Blink-side logic will take care of applying
-  // necessary changes to the other two ancestors.
-  if (enter_fullscreen &&
-      SiteIsolationPolicy::AreCrossProcessFramesPossible()) {
-    std::set<SiteInstance*> notified_instances;
-    notified_instances.insert(GetSiteInstance());
-    for (FrameTreeNode* node = frame_tree_node_; node->parent();
-         node = node->parent()) {
-      SiteInstance* parent_site_instance =
-          node->parent()->current_frame_host()->GetSiteInstance();
-      if (ContainsKey(notified_instances, parent_site_instance))
-        continue;
-
-      RenderFrameProxyHost* child_proxy =
-          node->render_manager()->GetRenderFrameProxyHost(parent_site_instance);
-      child_proxy->Send(
-          new FrameMsg_WillEnterFullscreen(child_proxy->GetRoutingID()));
-      notified_instances.insert(parent_site_instance);
-    }
-  }
-
-  // TODO(alexmos): See if this can use the last committed origin instead.
   if (enter_fullscreen)
     delegate_->EnterFullscreenMode(last_committed_url().GetOrigin());
   else
@@ -1820,12 +1787,6 @@
 
   // The previous call might change the fullscreen state. We need to make sure
   // the renderer is aware of that, which is done via the resize message.
-  // Typically, this will be sent as part of the call on the |delegate_| above
-  // when resizing the native windows, but sometimes fullscreen can be entered
-  // without causing a resize, so we need to ensure that the resize message is
-  // sent in that case. We always send this to the main frame's widget, and if
-  // there are any OOPIF widgets, this will also trigger them to resize via
-  // frameRectsChanged.
   render_view_host_->GetWidget()->WasResized();
 }