Migrate Telemetry from beginWindowSnapshotPNG to Page.captureScreenshot

content/public/browser/render_widget_host.h

Index: content/public/browser/render_widget_host.h
diff --git a/content/public/browser/render_widget_host.h b/content/public/browser/render_widget_host.h
index fbddb79aa0aeab17036a6498bbd6f5015db2cec5..d6938f2424539ed1bdc8f05785b51c5a30d9ecca 100644
--- a/content/public/browser/render_widget_host.h
+++ b/content/public/browser/render_widget_host.h
@@ -294,6 +294,11 @@ class CONTENT_EXPORT RenderWidgetHost : public IPC::Sender {
       const gfx::Rect& src_subrect,
       const base::Callback<void(bool, const SkBitmap&)>& callback) = 0;
 
+  // Forces redraw in the renderer and when the update reaches the browser
+  // grabs snapshot from the compositor. Returns PNG-encoded snapshot.
+  virtual void GetSnapshotFromBrowser(
+      const base::Callback<void(const unsigned char*, size_t)> callback) = 0;
+
  protected:
   friend class RenderWidgetHostImpl;