[devtools] Remove device emulation background color override.

third_party/WebKit/Source/web/DevToolsEmulator.cpp

 // Copyright 2015 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 "web/DevToolsEmulator.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/frame/VisualViewport.h"
 #include "core/input/EventHandler.h"
@@ skipping 205 matching lines @@
       emulation_params_.device_scale_factor == params.device_scale_factor &&
       emulation_params_.offset == params.offset &&
       emulation_params_.scale == params.scale) {
     return;
   }
   if (emulation_params_.device_scale_factor != params.device_scale_factor ||
       !device_metrics_enabled_)
     GetMemoryCache()->EvictResources();
 
   emulation_params_ = params;
-
-  if (!device_metrics_enabled_) {
-    device_metrics_enabled_ = true;
-    if (params.view_size.width || params.view_size.height)
-      web_view_impl_->SetBackgroundColorOverride(Color::kDarkGray);

[dgozman, 2017/04/12 18:21:23]

Remove these methods from WebViewImpl as well?

[Eric Seckler, 2017/04/12 19:31:31]

After my recent refactorings of transparency overrides, these methods are now
actually used for a non-devtools purpose, too:
https://cs.chromium.org/chromium/src/content/renderer/render_view_impl.cc?l=2240

-  }
+  device_metrics_enabled_ = true;
 
   web_view_impl_->GetPage()->GetSettings().SetDeviceScaleAdjustment(
       calculateDeviceScaleAdjustment(params.view_size.width,
                                      params.view_size.height,
                                      params.device_scale_factor));
 
   if (params.screen_position == WebDeviceEmulationParams::kMobile)
     EnableMobileEmulation();
   else
     DisableMobileEmulation();
 
   web_view_impl_->SetCompositorDeviceScaleFactorOverride(
       params.device_scale_factor);
   UpdateRootLayerTransform();
   // TODO(dgozman): mainFrameImpl() is null when it's remote. Figure out how
   // we end up with enabling emulation in this case.
   if (web_view_impl_->MainFrameImpl()) {
     if (Document* document =
             web_view_impl_->MainFrameImpl()->GetFrame()->GetDocument())
       document->MediaQueryAffectingValueChanged();
   }
 }
 
 void DevToolsEmulator::DisableDeviceEmulation() {
   if (!device_metrics_enabled_)
     return;
 
   GetMemoryCache()->EvictResources();
   device_metrics_enabled_ = false;
-  web_view_impl_->ClearBackgroundColorOverride();
   web_view_impl_->GetPage()->GetSettings().SetDeviceScaleAdjustment(
       embedder_device_scale_adjustment_);
   DisableMobileEmulation();
   web_view_impl_->SetCompositorDeviceScaleFactorOverride(0.f);
   web_view_impl_->SetPageScaleFactor(1.f);
   UpdateRootLayerTransform();
   // mainFrameImpl() could be null during cleanup or remote <-> local swap.
   if (web_view_impl_->MainFrameImpl()) {
     if (Document* document =
             web_view_impl_->MainFrameImpl()->GetFrame()->GetDocument())
@@ skipping 284 matching lines @@
       last_pinch_anchor_css_.reset();
       last_pinch_anchor_dip_.reset();
     }
     return true;
   }
 
   return false;
 }
 
 }  // namespace blink