[UseZoomForDSF] Guest view support

content/browser/renderer_host/render_widget_host_impl.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_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 193 matching lines @@
       text_direction_canceled_(false),
       suppress_next_char_events_(false),
       pending_mouse_lock_request_(false),
       allow_privileged_mouse_lock_(false),
       has_touch_handler_(false),
       is_in_gesture_scroll_(false),
       received_paint_after_load_(false),
       next_browser_snapshot_id_(1),
       owned_by_render_frame_host_(false),
       is_focused_(false),
+      scale_input_to_viewport_(IsUseZoomForDSFEnabled()),
       hung_renderer_delay_(
           base::TimeDelta::FromMilliseconds(kHungRendererDelayMs)),
       new_content_rendering_delay_(
           base::TimeDelta::FromMilliseconds(kNewContentRenderingDelayMs)),
       mouse_wheel_coalesce_timer_(new base::ElapsedTimer()),
       weak_factory_(this) {
   CHECK(delegate_);
   CHECK_NE(MSG_ROUTING_NONE, routing_id_);
 
   std::pair<RoutingIDWidgetMap::iterator, bool> result =
@@ skipping 1033 matching lines @@
 
 void RenderWidgetHostImpl::GetWebScreenInfo(blink::WebScreenInfo* result) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::GetWebScreenInfo");
   if (view_)
     view_->GetScreenInfo(result);
   else
     RenderWidgetHostViewBase::GetDefaultScreenInfo(result);
   // TODO(sievers): find a way to make this done another way so the method
   // can be const.
   latency_tracker_.set_device_scale_factor(result->deviceScaleFactor);
-  if (IsUseZoomForDSFEnabled())
+  if (scale_input_to_viewport_)

[wjmaclean, 2016/01/20 19:41:54]

What is the advantage to storing this state? I guess it never changes during the
lifetime of the RWHI ...

[oshima, 2016/01/20 21:38:49]

It will change per RWHImpl instance. 

     input_router_->SetDeviceScaleFactor(result->deviceScaleFactor);
 }
 
 bool RenderWidgetHostImpl::GetScreenColorProfile(
     std::vector<char>* color_profile) {
   DCHECK(color_profile->empty());
   if (view_)
     return view_->GetScreenColorProfile(color_profile);
   return false;
 }
@@ skipping 968 matching lines @@
 }
 
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderWidgetHostImpl::GetParentNativeViewAccessible() {
   return delegate_ ? delegate_->GetParentNativeViewAccessible() : NULL;
 }
 #endif
 
 }  // namespace content