Clear renderer compositor trees if new page does not render in 4 seconds

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 611 matching lines @@
     IPC_MESSAGE_HANDLER(ViewMsg_WasHidden, OnWasHidden)
     IPC_MESSAGE_HANDLER(ViewMsg_WasShown, OnWasShown)
     IPC_MESSAGE_HANDLER(ViewMsg_Repaint, OnRepaint)
     IPC_MESSAGE_HANDLER(ViewMsg_SetTextDirection, OnSetTextDirection)
     IPC_MESSAGE_HANDLER(ViewMsg_Move_ACK, OnRequestMoveAck)
     IPC_MESSAGE_HANDLER(ViewMsg_UpdateScreenRects, OnUpdateScreenRects)
     IPC_MESSAGE_HANDLER(ViewMsg_SetViewportIntersection,
                         OnSetViewportIntersection)
     IPC_MESSAGE_HANDLER(ViewMsg_WaitForNextFrameForTests,
                         OnWaitNextFrameForTests)
+    IPC_MESSAGE_HANDLER(ViewMsg_ClearDisplayedContent, OnClearDisplayedContent)
     IPC_MESSAGE_HANDLER(InputMsg_RequestCompositionUpdate,
                         OnRequestCompositionUpdate)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDragEnter, OnDragTargetDragEnter)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDragOver, OnDragTargetDragOver)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDragLeave, OnDragTargetDragLeave)
     IPC_MESSAGE_HANDLER(DragMsg_TargetDrop, OnDragTargetDrop)
     IPC_MESSAGE_HANDLER(DragMsg_SourceEnded, OnDragSourceEnded)
     IPC_MESSAGE_HANDLER(DragMsg_SourceSystemDragEnded,
                         OnDragSourceSystemDragEnded)
 #if defined(OS_ANDROID)
@@ skipping 1666 matching lines @@
     // when the RenderWidget is swapped out. We should top sending IPCs from the
     // browser side (https://crbug.com/669219).
     // If there is no WebFrameWidget, then there will be no
     // InputMethodControllers for a WebLocalFrame.
     return nullptr;
   }
   return static_cast<blink::WebFrameWidget*>(GetWebWidget())
       ->getActiveWebInputMethodController();
 }
 
+void RenderWidget::OnClearDisplayedContent() {
+  if (compositor_) {
+    compositor_->ResetTrees();
+  }
+}
+
 }  // namespace content