Fix flakiness in DragAndDropBrowserTests

content/public/test/browser_test_utils.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_TEST_BROWSER_TEST_UTILS_H_
 #define CONTENT_PUBLIC_TEST_BROWSER_TEST_UTILS_H_
 
 #include <queue>
 #include <string>
 #include <vector>
@@ skipping 333 matching lines @@
                                   gfx::Point point);
 //
 // Waits until the cc::Surface associated with a guest/cross-process-iframe
 // has been drawn for the first time. Once this method returns it should be
 // safe to assume that events sent to the top-level RenderWidgetHostView can
 // be expected to properly hit-test to this surface, if appropriate.
 void WaitForGuestSurfaceReady(content::WebContents* web_contents);
 
 #endif
 
+// Waits until the cc::Surface associated with a cross-process child frame
+// has been drawn for the first time. Once this method returns it should be
+// safe to assume that events sent to the top-level RenderWidgetHostView can
+// be expected to properly hit-test to this surface, if appropriate.
+void WaitForChildFrameSurfaceReady(content::RenderFrameHost* child_frame);
+
 // Watches title changes on a WebContents, blocking until an expected title is
 // set.
 class TitleWatcher : public WebContentsObserver {
  public:
   // |web_contents| must be non-NULL and needs to stay alive for the
   // entire lifetime of |this|. |expected_title| is the title that |this|
   // will wait for.
   TitleWatcher(WebContents* web_contents,
                const base::string16& expected_title);
   ~TitleWatcher() override;
@@ skipping 405 matching lines @@
 
  private:
   PwnMessageHelper();  // Not instantiable.
 
   DISALLOW_COPY_AND_ASSIGN(PwnMessageHelper);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_BROWSER_TEST_UTILS_H_