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

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 1195a70fc3ddd310cf43fc28ad7a9eb74bcc4bbe..11abe4fa89267b2973eb272c6134fca6164cf35b 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -6652,6 +6652,11 @@ std::unique_ptr<blink::WebURLLoader> RenderFrameImpl::CreateURLLoader() {
   return blink::Platform::Current()->CreateURLLoader();
 }
 
+void RenderFrameImpl::DraggableRegionsChanged() {
+  for (auto& observer : observers_)
+    observer.DraggableRegionsChanged();
+}
+
 blink::WebPageVisibilityState RenderFrameImpl::GetVisibilityState() const {
   return VisibilityState();
 }