Fix webview crash on attempt to scroll.

content/public/test/browser_test_utils.cc

 // 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.
 
 #include "content/public/test/browser_test_utils.h"
 
 #include <stddef.h>
 #include <tuple>
 #include <utility>
 
@@ skipping 505 matching lines @@
   widget_host->ForwardGestureEvent(scroll_update);
 
   blink::WebGestureEvent scroll_end;
   scroll_end.type = blink::WebGestureEvent::GestureScrollEnd;
   scroll_end.sourceDevice = blink::WebGestureDeviceTouchpad;
   scroll_end.x = point.x() + delta.x();
   scroll_end.y = point.y() + delta.y();
   widget_host->ForwardGestureEvent(scroll_end);
 }
 
+void SimulateGestureFlingSequence(WebContents* web_contents,
+                                  const gfx::Point& point,
+                                  const gfx::Vector2dF& velocity) {
+  RenderWidgetHostImpl* widget_host = RenderWidgetHostImpl::From(
+      web_contents->GetRenderViewHost()->GetWidget());
+
+  blink::WebGestureEvent scroll_begin;
+  scroll_begin.type = blink::WebGestureEvent::GestureScrollBegin;
+  scroll_begin.sourceDevice = blink::WebGestureDeviceTouchpad;
+  scroll_begin.x = point.x();
+  scroll_begin.y = point.y();
+  widget_host->ForwardGestureEvent(scroll_begin);
+
+  blink::WebGestureEvent scroll_end;
+  scroll_end.type = blink::WebGestureEvent::GestureScrollEnd;
+  scroll_end.sourceDevice = blink::WebGestureDeviceTouchpad;
+  scroll_end.x = point.x();
+  scroll_end.y = point.y();
+  widget_host->ForwardGestureEvent(scroll_end);
+
+  blink::WebGestureEvent fling_start;
+  fling_start.type = blink::WebGestureEvent::GestureFlingStart;
+  fling_start.sourceDevice = blink::WebGestureDeviceTouchpad;
+  fling_start.x = point.x();
+  fling_start.y = point.y();
+  fling_start.data.flingStart.targetViewport = false;
+  fling_start.data.flingStart.velocityX = velocity.x();
+  fling_start.data.flingStart.velocityY = velocity.y();
+  widget_host->ForwardGestureEvent(fling_start);
+}
+
 void SimulateTapAt(WebContents* web_contents, const gfx::Point& point) {
   blink::WebGestureEvent tap;
   tap.type = blink::WebGestureEvent::GestureTap;
   tap.sourceDevice = blink::WebGestureDeviceTouchpad;
   tap.x = point.x();
   tap.y = point.y();
   tap.modifiers = blink::WebInputEvent::ControlKey;
   RenderWidgetHostImpl* widget_host = RenderWidgetHostImpl::From(
       web_contents->GetRenderViewHost()->GetWidget());
   widget_host->ForwardGestureEvent(tap);
@@ skipping 722 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (ack_result_ != INPUT_EVENT_ACK_STATE_UNKNOWN)
     return ack_result_;
   base::RunLoop run_loop;
   base::AutoReset<base::Closure> reset_quit(&quit_, run_loop.QuitClosure());
   run_loop.Run();
   return ack_result_;
 }
 
 }  // namespace content