Stretching NativeViewHost, and misc tab capture fixes.

content/browser/media/capture/web_contents_video_capture_device.cc

Index: content/browser/media/capture/web_contents_video_capture_device.cc
diff --git a/content/browser/media/capture/web_contents_video_capture_device.cc b/content/browser/media/capture/web_contents_video_capture_device.cc
index 336ec0ee10e81821ee86dcedba39d6ba8ea5214c..f4b73f2bc31d76256ebaaeccc83a627e02707c27 100644
--- a/content/browser/media/capture/web_contents_video_capture_device.cc
+++ b/content/browser/media/capture/web_contents_video_capture_device.cc
@@ -552,9 +552,8 @@ void WebContentsCaptureMachine::Capture(
     return;
   }
 
-  const gfx::Size view_size = view->GetViewBounds().size();
   view->CopyFromCompositingSurfaceToVideoFrame(
-      gfx::Rect(view_size), std::move(target),
+      gfx::Rect(), std::move(target),
       base::Bind(&WebContentsCaptureMachine::DidCopyToVideoFrame,
                  weak_ptr_factory_.GetWeakPtr(), start_time, deliver_frame_cb));
 }
@@ -686,16 +685,13 @@ void WebContentsCaptureMachine::UpdateCaptureSize() {
   if (!view)
     return;
 
-  // Convert the view's size from the DIP coordinate space to the pixel
-  // coordinate space.  When the view is being rendered on a high-DPI display,
-  // this allows the high-resolution image detail to propagate through to the
+  // The capture size is not the view's size in DIP coordinates, but instead
+  // based on the backing store. Thus, when a view is being rendered on a high-
+  // DPI display, the high-resolution image detail will propagate through to the
   // captured video.
-  const gfx::Size view_size = view->GetViewBounds().size();
-  const gfx::Size physical_size = gfx::ConvertSizeToPixel(
-      ui::GetScaleFactorForNativeView(view->GetNativeView()), view_size);
-  VLOG(1) << "Computed physical capture size (" << physical_size.ToString()
-          << ") from view size (" << view_size.ToString() << ").";
-
+  const gfx::Size physical_size =
+      static_cast<RenderWidgetHostViewBase*>(view)->GetPhysicalBackingSize();
+  VLOG(1) << "Physical capture size of view is " << physical_size.ToString();
   oracle_proxy_->UpdateCaptureSize(physical_size);
 }