Require ACK for editor-related changes not originating from browser.

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 4f20cc60140334eda7fd819193c368bb4b76af10..26dc7cc1886d512d1d3de05a97dc24bea6355409 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -204,6 +204,11 @@ class CONTENT_EXPORT RenderWidget
     SHOW_IME_IF_NEEDED
   };
 
+  enum ImeAck {
+    SEND_IME_ACK,
+    NO_IME_ACK

[jam, 2013/07/31 20:57:09]

i realize this is the convention in blink, but in chromium the most common thing
is just to use bools.. i'd even prefer we switch ShowIme to bool as well

[nyquist, 2013/08/01 23:11:04]

Done.

+  };
+
   // Handle common setup/teardown for handling IME events.
   void StartHandlingImeEvent();
   void FinishHandlingImeEvent();
@@ -326,7 +331,19 @@ class CONTENT_EXPORT RenderWidget
 #if defined(OS_ANDROID)
   void OnImeBatchStateChanged(bool is_begin);
   void OnShowImeIfNeeded();
+
+  // Whenever an IME event that needs an acknowledgement is sent to the browser,
+  // the number of outstanding IME events that needs acknowledgement should be
+  // incremented. All IME events will be dropped until we receive an ack from
+  // the browser.
+  void IncrementOutstandingImeEventAcks();
+
+  // Called by the browser process for every required IME acknowledgement.
+  void OnImeEventAck();
 #endif
+  // Returns whether we currently should handle an IME event.
+  bool ShouldHandleImeEvent();
+
   void OnSnapshot(const gfx::Rect& src_subrect);
   void OnSetBrowserRenderingStats(const BrowserRenderingStats& stats);
 
@@ -408,7 +425,7 @@ class CONTENT_EXPORT RenderWidget
 #if defined(OS_ANDROID)
   // |show_ime_if_needed| should be SHOW_IME_IF_NEEDED iff the update may cause
   // the ime to be displayed, e.g. after a tap on an input field on mobile.
-  void UpdateTextInputState(ShowIme show_ime);
+  void UpdateTextInputState(ShowIme show_ime, ImeAck ack);
 #endif
 
   // Checks if the selection bounds have been changed. If they are changed,
@@ -717,6 +734,13 @@ class CONTENT_EXPORT RenderWidget
 
   uint32 next_output_surface_id_;
 
+#if defined(OS_ANDROID)
+  // A counter for number of outstanding messages from the renderer to the
+  // browser regarding IME-type events that have not been acknowledged by the
+  // browser. If this value is not 0 IME events will be dropped.
+  int outstanding_ime_acks_;
+#endif
+
   base::WeakPtrFactory<RenderWidget> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);