Fix OOPIFs on Android

content/browser/renderer_host/render_widget_host_view_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 
 #include <android/bitmap.h>
 
 #include <utility>
 
@@ skipping 1285 matching lines @@
 
   observing_root_window_ = true;
   if (host_)
     host_->Send(new ViewMsg_SetBeginFramePaused(host_->GetRoutingID(), false));
   content_view_core_->GetWindowAndroid()->AddObserver(this);
 
   // Clear existing vsync requests to allow a request to the new window.
   uint32_t outstanding_vsync_requests = outstanding_vsync_requests_;
   outstanding_vsync_requests_ = 0;
   RequestVSyncUpdate(outstanding_vsync_requests);
+
+  ui::WindowAndroidCompositor* compositor =
+      content_view_core_->GetWindowAndroid()->GetCompositor();

[enne (OOO), 2016/09/23 22:58:09]

Can I assume that there's always a compositor at this point? It's a little weird
to me that RenderWidgetHostViewAndroid never gets OnAttachCompositor messages,
but maybe it starts observing after the compositor is attached to the window.

[no sievers, 2016/09/23 23:16:09]

I don't trust the logic here with 'observing' but maybe you can sidestep it
since you only care about making sure that you catch all cases of attaching to a
different browser compositor.

So instead of here, I'd register the namespace in the RWHVA constructor
(null-check for compositor because of webview).

Then I'd simply unregister the namespace in OnDetachCompositor() and register it
in OnAttachCompositor().

It's possible that it will cause some redundant calls. I assume that's fine for
unregister. But not sure about registering twice. Maybe you need to track the
current compositor SurfaceClientId here?

+  delegated_frame_host_->RegisterSurfaceNamespaceHierarchy(
+      compositor->GetSurfaceClientId());
 }
 
 void RenderWidgetHostViewAndroid::StopObservingRootWindow() {
   if (!content_view_core_ || !(content_view_core_->GetWindowAndroid())) {
     DCHECK(!observing_root_window_);
     return;
   }
 
   if (!observing_root_window_)
     return;
 
   // Reset window state variables to their defaults.
   is_window_activity_started_ = true;
   is_window_visible_ = true;
   observing_root_window_ = false;
   if (host_)
     host_->Send(new ViewMsg_SetBeginFramePaused(host_->GetRoutingID(), true));
   content_view_core_->GetWindowAndroid()->RemoveObserver(this);
+  delegated_frame_host_->UnregisterSurfaceNamespaceHierarchy();
 }
 
 void RenderWidgetHostViewAndroid::SendBeginFrame(base::TimeTicks frame_time,
                                                  base::TimeDelta vsync_period) {
   TRACE_EVENT1("cc", "RenderWidgetHostViewAndroid::SendBeginFrame",
                "frame_time_us", frame_time.ToInternalValue());
 
   // Synchronous compositor does not use deadline-based scheduling.
   // TODO(brianderson): Replace this hardcoded deadline after Android
   // switches to Surfaces and the Browser's commit isn't in the critcal path.
@@ skipping 546 matching lines @@
     case ui::MotionEvent::ACTION_UP:
     case ui::MotionEvent::ACTION_POINTER_UP:
       UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.TOUCH_RELEASED",
                                   delta.InMicroseconds(), 1, 1000000, 50);
     default:
       return;
   }
 }
 
 }  // namespace content