Move content offset to ViewAndroid

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index adf4451262e8977929e0cf626417eb3abdf2aad5..40b3d3f42daa81493305003c2077138e9917fa63 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -2345,8 +2345,13 @@ void RenderWidgetHostImpl::DidReceiveRendererFrame() {
 void RenderWidgetHostImpl::WindowSnapshotReachedScreen(int snapshot_id) {
   DCHECK(base::MessageLoopForUI::IsCurrent());
 
-  gfx::Rect view_bounds = GetView()->GetViewBounds();
-  gfx::Rect snapshot_bounds(view_bounds.size());
+#if defined(ANDROID)
+  // On Android, call sites should pass in the bounds with correct offset
+  // to capture the intended content area.
+  gfx::Rect snapshot_bounds(GetView()->GetViewBounds());

[boliu, 2016/12/22 21:14:59]

Feels like GrabViewSnapshotAsync should grab the offset directly from
ViewAndroid, then this code doesn't need to be specialized. Also
RWHVA::GetViewBounds don't need to change either I think?

[boliu, 2016/12/22 21:28:54]

Oh, I see sievers complained about the translation in
https://codereview.chromium.org/2219823002/diff/1/ui/snapshot/snapshot_androi...

So maybe not do what I said above..

Documentation for GrabViewSnapshotAsync says source_rect is in *layer* space.
This means that right now RWHVA::GetViewBounds is wrong. The translation should
be moved out of GetViewBounds to here, because we don't want to read the entire
layer. Sucks to have platform-specific code here, but I guess that makes sense
because only android has top controls.

Also did you test all the cases that he mentioned in that comment, and
everything still works as expected after this CL?

[Jinsuk Kim, 2017/01/03 07:07:48]

I take it that you want the change in RWVHA::GetViewBounds() reverted?
Yes, quoting my own comment in case you might have missed it:

+#else
+  gfx::Rect snapshot_bounds(GetView()->GetViewBounds().size());
+#endif
 
   std::vector<unsigned char> png;
   if (ui::GrabViewSnapshot(