[UseZoomForDSF] Guest view support

content/browser/frame_host/render_widget_host_view_guest.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/frame_host/render_widget_host_view_guest.h"
 
 #include <utility>
 
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 44 matching lines @@
 }  // namespace
 
 RenderWidgetHostViewGuest::RenderWidgetHostViewGuest(
     RenderWidgetHost* widget_host,
     BrowserPluginGuest* guest,
     base::WeakPtr<RenderWidgetHostViewBase> platform_view)
     : RenderWidgetHostViewChildFrame(widget_host),
       // |guest| is NULL during test.
       guest_(guest ? guest->AsWeakPtr() : base::WeakPtr<BrowserPluginGuest>()),
       platform_view_(platform_view) {
+  // Inputs for guest view are already scaled.
+  host_->set_scale_input_to_viewport(false);

[no sievers, 2016/01/26 19:42:35]

Is it possible for this |host_| to host an interstitial page or other kind of
view?

I'm wondering if it's better for the RWHV to query the RWHV for this flag. wdyt?

 }
 
 RenderWidgetHostViewGuest::~RenderWidgetHostViewGuest() {
 }
 
 bool RenderWidgetHostViewGuest::OnMessageReceivedFromEmbedder(
     const IPC::Message& message,
     RenderWidgetHostImpl* embedder) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP_WITH_PARAM(RenderWidgetHostViewGuest, message,
@@ skipping 628 matching lines @@
     if (gesture_event.type == blink::WebInputEvent::GestureScrollUpdate &&
         gesture_event.data.scrollUpdate.inertial) {
       return;
     }
     host_->ForwardGestureEvent(gesture_event);
     return;
   }
 }
 
 }  // namespace content