Move handling of DraggableRegionsChanged notification from "view" to "frame".

extensions/renderer/extension_frame_helper.cc

Index: extensions/renderer/extension_frame_helper.cc
diff --git a/extensions/renderer/extension_frame_helper.cc b/extensions/renderer/extension_frame_helper.cc
index da47e687f5662c0d8eefb6830a860edf971c2689..b409b1c3c46244b0c3fa0c2b2c3f4095090ca0a0 100644
--- a/extensions/renderer/extension_frame_helper.cc
+++ b/extensions/renderer/extension_frame_helper.cc
@@ -8,6 +8,7 @@
 #include "base/strings/string_util.h"
 #include "base/timer/elapsed_timer.h"
 #include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_view.h"
 #include "extensions/common/api/messaging/message.h"
 #include "extensions/common/api/messaging/port_id.h"
 #include "extensions/common/constants.h"
@@ -335,4 +336,19 @@ void ExtensionFrameHelper::OnDestruct() {
   delete this;
 }
 
+void ExtensionFrameHelper::DraggableRegionsChanged() {
+  blink::WebVector<blink::WebDraggableRegion> webregions =
+      render_frame()->GetWebFrame()->GetDocument().DraggableRegions();
+  std::vector<DraggableRegion> regions;
+  for (size_t i = 0; i < webregions.size(); ++i) {
+    DraggableRegion region;
+    render_frame()->GetRenderView()->ConvertViewportToWindowViaWidget(

[alexmos, 2017/06/08 21:19:00]

Is this going to work for a swapped-out RenderView?  I would think this should
instead use something like
render_frame()->GetRenderWidget()->ConvertViewportToWindow(), though we don't
publicly expose RenderWidget. :(  I don't know if there's a behavioral
difference in practice for the conversion (e.g., I don't remember if we set
things like GetOriginalDeviceScaleFactor for swapped-out RVs or not).  James or
Ken would probably know.

[Łukasz Anforowicz, 2017/06/08 22:27:13]

Thanks for catching this.

I guess one option would be to bail out early if the main frame is not a local
frame.  (before this CL, such situation would result in a crash).

Ken: Could you please comment on what to do here?

[kenrb, 2017/06/09 15:43:25]

As far as I know, using ConvertViewportToWindowViaWidget() usage should be okay.
Swapped-out RenderViews should still get Resize messages with correct
ResizeParams. In Blink the information gets a bit sparser because WebViewImpl's
resize code bails early when mainFrame() is remote, but in content/ the
information is there.

A second question I see is whether, in an OOPIF process, the
Document::DraggableRegions() actually returns regions in Viewport coordinates,
which this code assumes when it converts from Viewport to Window coords. I just
took a quick look at the code, and I think the answer is (mostly) yes, which was
a happy surprise. I think that works because of the IntersectionObserver changes
I landed earlier this year, which taught Blink layout code to successfully map
coords to the root viewport. I say 'mostly yes' because there might be skew if
there are transforms applied to the OOPIF by the embedding frame. We don't
currently take that into account.

+        &webregions[i].bounds);
+    region.bounds = webregions[i].bounds;
+    region.draggable = webregions[i].draggable;
+    regions.push_back(region);
+  }
+  Send(new ExtensionHostMsg_UpdateDraggableRegions(routing_id(), regions));
+}
+
 }  // namespace extensions