Clear needs_resize_ack when clearing DeviceMetricsOverride.

content/renderer/devtools/render_widget_screen_metrics_emulator.cc

 // Copyright 2016 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/renderer/devtools/render_widget_screen_metrics_emulator.h"
 
 #include "content/common/resize_params.h"
 #include "content/public/common/context_menu_params.h"
 #include "content/renderer/devtools/render_widget_screen_metrics_emulator_delegate.h"
 
 namespace content {
 
 RenderWidgetScreenMetricsEmulator::RenderWidgetScreenMetricsEmulator(
     RenderWidgetScreenMetricsEmulatorDelegate* delegate,
     const blink::WebDeviceEmulationParams& params,
     const ResizeParams& resize_params,
     const gfx::Rect& view_screen_rect,
     const gfx::Rect& window_screen_rect)
     : delegate_(delegate),
       emulation_params_(params),
       scale_(1.f),
       original_resize_params_(resize_params),
       original_view_screen_rect_(view_screen_rect),
       original_window_screen_rect_(window_screen_rect) {
 }
 
 RenderWidgetScreenMetricsEmulator::~RenderWidgetScreenMetricsEmulator() {
+  // needs_resize_ack was handled during OnResize() and may cause a DCHECK to
+  // fail in RenderWidget if not cleared (crbug.com/635560).
+  original_resize_params_.needs_resize_ack = false;
   delegate_->Resize(original_resize_params_);
   delegate_->SetScreenMetricsEmulationParameters(false, emulation_params_);
   delegate_->SetScreenRects(original_view_screen_rect_,
                             original_window_screen_rect_);
 }
 
 void RenderWidgetScreenMetricsEmulator::ChangeEmulationParams(
     const blink::WebDeviceEmulationParams& params) {
   emulation_params_ = params;
   Apply();
@@ skipping 130 matching lines @@
 
 gfx::Rect RenderWidgetScreenMetricsEmulator::AdjustValidationMessageAnchor(
     const gfx::Rect& anchor) {
   gfx::Rect scaled = gfx::ScaleToEnclosedRect(anchor, scale_);
   scaled.set_x(scaled.x() + offset_.x());
   scaled.set_y(scaled.y() + offset_.y());
   return scaled;
 }
 
 }  // namespace content