Update Mac plugin IME handling to match updated spec

third_party/mozilla/ComplexTextInputPanel.mm

 /*
  * Copyright (C) 2009 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 80 matching lines @@
 {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   
   [mInputTextView release];
   
   [super dealloc];
 }
 
 - (void)keyboardInputSourceChanged:(NSNotification *)notification
 {
-  [mInputTextView setString:@""];
-  [self orderOut:nil];
+  [self cancelComposition];
 }
 
 - (BOOL)interpretKeyEvent:(NSEvent*)event string:(NSString**)string
 {
   BOOL hadMarkedText = [mInputTextView hasMarkedText];
 
   *string = nil;
 
   if (![[mInputTextView inputContext] handleEvent:event])
     return NO;
 
   if ([mInputTextView hasMarkedText]) {
     // Don't show the input method window for dead keys
     if ([[event characters] length] > 0)
       [self orderFront:nil];
 
     return YES;
   } else {
     [self orderOut:nil];
 
     NSString *text = [[mInputTextView textStorage] string];
     if ([text length] > 0)
       *string = [[text copy] autorelease];
   }
 
   [mInputTextView setString:@""];
   return hadMarkedText;
 }
 
-- (void)cancelInput
-{
-  [self orderOut:nil];
-  [mInputTextView setString:@""];
-}
-
 - (NSTextInputContext*)inputContext
 {
   return [mInputTextView inputContext];
 }
 
+- (void)cancelComposition
+{
+  [mInputTextView setString:@""];
+  [self orderOut:nil];
+}
+
+- (BOOL)inComposition
+{
+  return [mInputTextView hasMarkedText];
+}
+
 @end