DelegatedFrameHost: drop renderer frame on resize if hidden

content/browser/compositor/delegated_frame_host.cc

 // Copyright 2014 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/compositor/delegated_frame_host.h"
 
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
@@ skipping 205 matching lines @@
   // the completion of latency infos (such as when taking a Snapshot.)
   if (can_lock_compositor_ == NO_PENDING_RENDERER_FRAME ||
       can_lock_compositor_ == NO_PENDING_COMMIT ||
       !resize_lock_.get())
     return false;
 
   return size_in_dip != resize_lock_->expected_size();
 }
 
 void DelegatedFrameHost::WasResized() {
+  if (client_->DesiredFrameSize() != current_frame_size_in_dip_ &&
+      client_->GetHost()->is_hidden())
+    EvictDelegatedFrame();
   MaybeCreateResizeLock();
 }
 
 gfx::Size DelegatedFrameHost::GetRequestedRendererSize() const {
   if (resize_lock_)
     return resize_lock_->expected_size();
   else
     return client_->DesiredFrameSize();
 }
 
@@ skipping 669 matching lines @@
   if (frame_provider_.get()) {
     new_layer->SetShowDelegatedContent(frame_provider_.get(),
                                        current_frame_size_in_dip_);
   }
   if (!surface_id_.is_null()) {
     new_layer->SetShowSurface(surface_id_, current_frame_size_in_dip_);
   }
 }
 
 }  // namespace content