[UseZoomForDSF] Guest view support

content/renderer/child_frame_compositing_helper.cc

Index: content/renderer/child_frame_compositing_helper.cc
diff --git a/content/renderer/child_frame_compositing_helper.cc b/content/renderer/child_frame_compositing_helper.cc
index 408fc0817b9fc0d86e739dd89fab2cdf9eafa872..3957cefe3b655f26fa17e8486101a15a3537758b 100644
--- a/content/renderer/child_frame_compositing_helper.cc
+++ b/content/renderer/child_frame_compositing_helper.cc
@@ -18,6 +18,7 @@
 #include "cc/resources/single_release_callback.h"
 #include "content/child/thread_safe_sender.h"
 #include "content/common/browser_plugin/browser_plugin_messages.h"
+#include "content/common/content_switches_internal.h"
 #include "content/common/frame_messages.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/renderer/browser_plugin/browser_plugin.h"
@@ -314,6 +315,12 @@ void ChildFrameCompositingHelper::OnSetSurface(
   scoped_refptr<cc::SurfaceLayer> surface_layer =
       cc::SurfaceLayer::Create(cc_blink::WebLayerImpl::LayerSettings(),
                                satisfy_callback, require_callback);
+  // TODO(oshima): This is a stopgap fix so that the compositor does not
+  // scaledown the content when 2x frame data is added to 1x parent frame data.
+  // Fix this in cc/.
+  if (IsUseZoomForDSFEnabled())
+    scale_factor = 1.0f;
+
   surface_layer->SetSurfaceId(surface_id, scale_factor, frame_size);
   blink::WebLayer* layer = new cc_blink::WebLayerImpl(surface_layer);
   UpdateWebLayer(layer);