Fix set_area sizes for RequestCopyOfOutput, and related tests.

content/browser/renderer_host/render_widget_host_view_base.h

Index: content/browser/renderer_host/render_widget_host_view_base.h
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index 15a055d2e03f1decffe6359997a4dbe1194f9c7e..c0f9fecb597280c9a7b57109904d17eba57d52fa 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -244,13 +244,12 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
   virtual void ScrollOffsetChanged() = 0;
 
   // Copies the contents of the compositing surface into the given
-  // (uninitialized) PlatformCanvas if any.
-  // The rectangle region specified with |src_subrect| is copied from the
-  // contents, scaled to |dst_size|, and written to |output|.
-  // |callback| is invoked with true on success, false otherwise. |output| can
-  // be initialized even on failure.
-  // A smaller region than |src_subrect| may be copied if the underlying surface
-  // is smaller than |src_subrect|.
+  // (uninitialized) PlatformCanvas if any. |src_subrect| specified in DIP
+  // coordinates, is the region copied from the contents, scaled to |dst_size|
+  // (in physical pixels), and written to |output|. |callback| is invoked with
+  // true on success, false otherwise. |output| can be initialized even on
+  // failure. A smaller region than |src_subrect| may be copied if the
+  // underlying surface is smaller than |src_subrect|.
   // NOTE: |callback| is called asynchronously.
   virtual void CopyFromCompositingSurface(
       const gfx::Rect& src_subrect,
@@ -258,13 +257,13 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
       const base::Callback<void(bool, const SkBitmap&)>& callback,
       const SkColorType color_type) = 0;
 
-  // Copies a given subset of the compositing surface's content into a YV12
-  // VideoFrame, and invokes a callback with a success/fail parameter. |target|
-  // must contain an allocated, YV12 video frame of the intended size. If the
-  // copy rectangle does not match |target|'s size, the copied content will be
-  // scaled and letterboxed with black borders. The copy will happen
-  // asynchronously. This operation will fail if there is no available
-  // compositing surface.
+  // Copies the given rectangular region, specified with |src_subrect| in DIP
+  // coordinates, of the compositing surface's content into a YV12 VideoFrame,
+  // and invokes a callback with a success/fail parameter. |target| must contain
+  // an allocated, YV12 video frame of the intended size. If the copy rectangle
+  // does not match |target|'s size, the copied content will be scaled and
+  // letterboxed with black borders. The copy will happen asynchronously. This
+  // operation will fail if there is no available compositing surface.
   virtual void CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,