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 30308736a76bdfb0ec9591ac8bcbaa62f651856e..a5eadee9be1e2f57cd44cad18945348c03c5621e 100644
--- a/content/public/browser/render_widget_host.h
+++ b/content/public/browser/render_widget_host.h
@@ -292,6 +292,11 @@ class CONTENT_EXPORT RenderWidgetHost : public IPC::Sender {
 
   virtual SkBitmap::Config PreferredReadbackFormat() = 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;