cc: PushProperties on viewport size change

cc/trees/layer_tree_host.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 325 matching lines @@
 
   sync_tree->set_top_controls_shrink_blink_size(
       top_controls_shrink_blink_size_);
   sync_tree->set_top_controls_height(top_controls_height_);
   sync_tree->PushTopControlsFromMainThread(top_controls_shown_ratio_);
 
   host_impl->SetUseGpuRasterization(UseGpuRasterization());
   host_impl->set_gpu_rasterization_status(GetGpuRasterizationStatus());
   RecordGpuRasterizationHistogram();
 
+  // When we are using GPU rasterization, tile size is based on the viewport
+  // width.  We could have layers that change in size, but are not invalidated
+  // because no layout is required.  When this happens, we need to notify the
+  // layers that they require a PushProperties to resize the tiles correctly.
+  if (root_layer() &&
+      device_viewport_size_ != host_impl->device_viewport_size() &&
+      UseGpuRasterization()) {
+    LayerTreeHostCommon::CallFunctionForSubtree(root_layer(), [](Layer* layer) {
+      layer->OnDeviceViewportSizeChanged();
+    });
+  }
+
   host_impl->SetViewportSize(device_viewport_size_);
   host_impl->SetDeviceScaleFactor(device_scale_factor_);
   host_impl->SetDebugState(debug_state_);
   if (pending_page_scale_animation_) {
     sync_tree->SetPendingPageScaleAnimation(
         pending_page_scale_animation_.Pass());
   }
 
   if (!ui_resource_request_queue_.empty()) {
     sync_tree->set_ui_resource_request_queue(ui_resource_request_queue_);
@@ skipping 921 matching lines @@
     bool children_need_begin_frames) const {
   proxy_->SetChildrenNeedBeginFrames(children_need_begin_frames);
 }
 
 void LayerTreeHost::SendBeginFramesToChildren(
     const BeginFrameArgs& args) const {
   client_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc