Fix OSK flickering issue

content/renderer/render_widget.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_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 65 matching lines @@
 }
 
 namespace scheduler {
 class RenderWidgetSchedulingState;
 }
 
 namespace content {
 class CompositorDependencies;
 class ExternalPopupMenu;
 class FrameSwapMessageQueue;
+class ImeEventGuard;
 class PepperPluginInstanceImpl;
 class RenderFrameImpl;
 class RenderFrameProxy;
 class RenderWidgetCompositor;
 class RenderWidgetTest;
 class ResizingModeSelector;
 struct ContextMenuParams;
 struct DidOverscrollParams;
 struct WebPluginGeometry;
 
@@ skipping 143 matching lines @@
   // This mechanism is not a drop-in replacement for IPC: messages sent this way
   // will not be automatically available to BrowserMessageFilter, for example.
   // FIFO ordering is preserved between messages enqueued with the same
   // |policy|, the ordering between messages enqueued for different policies is
   // undefined.
   //
   // |msg| message to send, ownership of |msg| is transferred.
   // |policy| see the comment on MessageDeliveryPolicy.
   void QueueMessage(IPC::Message* msg, MessageDeliveryPolicy policy);
 
-  // Handle common setup/teardown for handling IME events.
-  void StartHandlingImeEvent();
-  void FinishHandlingImeEvent();
+  // Handle start and finish of IME event guard.
+  void OnImeEventGuardStart(ImeEventGuard* guard);
+  void OnImeEventGuardFinish(ImeEventGuard* guard);
 
   // Returns whether we currently should handle an IME event.
   bool ShouldHandleImeEvent();
 
   // Called by the compositor when page scale animation completed.
   virtual void DidCompletePageScaleAnimation() {}
 
   // When paused in debugger, we send ack for mouse event early. This ensures
   // that we continue receiving mouse moves and pass them to debugger. Returns
   // whether we are paused in mouse move event and have sent the ack.
@@ skipping 394 matching lines @@
 
   // Are we currently handling an input event?
   bool handling_input_event_;
 
   // Used to intercept overscroll notifications while an event is being
   // handled. If the event causes overscroll, the overscroll metadata can be
   // bundled in the event ack, saving an IPC.  Note that we must continue
   // supporting overscroll IPC notifications due to fling animation updates.
   scoped_ptr<DidOverscrollParams>* handling_event_overscroll_;
 
-  // Are we currently handling an ime event?
-  bool handling_ime_event_;
+  // It is possible that one ImeEventGuard is nested inside another
+  // ImeEventGuard. We keep track of the outermost one, and update it as needed.
+  ImeEventGuard* ime_event_guard_;
 
   // Type of the input event we are currently handling.
   blink::WebInputEvent::Type handling_event_type_;
 
   // Whether we should not send ack for the current mouse move.
   bool ignore_ack_for_mouse_move_from_debugger_;
 
   // True if we have requested this widget be closed.  No more messages will
   // be sent, except for a Close.
   bool closing_;
@@ skipping 119 matching lines @@
 
   scoped_ptr<scheduler::RenderWidgetSchedulingState>
       render_widget_scheduling_state_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_