Fix OSK flickering issue

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index bb917e53dbd4630419258f05aa4b0d9b24ba7d4f..5ba7aca8030502cd966b829ebb6268cf9618f865 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -244,9 +244,9 @@ class CONTENT_EXPORT RenderWidget
   // |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();
+  void OnImeEventGuardFinish(bool from_non_ime);
 
   // Returns whether we currently should handle an IME event.
   bool ShouldHandleImeEvent();
@@ -661,8 +661,12 @@ class CONTENT_EXPORT RenderWidget
   // 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_;
+  // The number of IME events we are handling now.
+  int ime_guard_count_;
+  // We intentionally ignore text input update while we are handling IME events,
+  // but show_ime should be effective even if it was set in the middle of
+  // ignored state updates.
+  bool pending_show_ime_if_needed_;
 
   // Type of the input event we are currently handling.
   blink::WebInputEvent::Type handling_event_type_;
@@ -759,6 +763,11 @@ class CONTENT_EXPORT RenderWidget
   // by script etc., not by user input.
   bool text_field_is_dirty_;
 
+  // AdapterInputConnection make real changes only when it's not originating
+  // from IME. We want non-keyboard events (e.g., long-press events) to be
+  // treated as NOT originating from IME, when we finish handling these events.
+  bool pending_update_from_non_ime_;
+
   // Stores the history of text input infos from the last ACK'ed one from the
   // current one. The size is the number of pending ACKs plus one, since we
   // intentionally keep the last ack'd value to know what the browser is