Make backspace not go back while IME is active.

chrome/browser/tab_contents/tab_contents_view_mac.mm

 // Copyright (c) 2006-2008 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.
 
 #import <Carbon/Carbon.h>
 
 #include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 
 #include <string>
 
@@ skipping 293 matching lines @@
 
 - (void)setCurrentDragOperation:(NSDragOperation)operation {
   [dropTarget_ setCurrentOperation:operation];
 }
 
 - (TabContents*)tabContents {
   return tabContentsView_->tab_contents();
 }
 
 - (void)processKeyboardEvent:(NativeWebKeyboardEvent*)wkEvent {
+  if (wkEvent->skip_in_browser)
+    return;
+
   NSEvent* event = wkEvent->os_event;
 
   if ([event type] == NSKeyDown && ([event modifierFlags] & NSCommandKeyMask)) {
     // We need to dispatch this to the menu.
     if ([[NSApp mainMenu] performKeyEquivalent:event])
       return;
   }
 
   // Cmd-` is not in the menu and it's apparently handled by |NSApp sendEvent|
   // if the application doesn't swallow it. We do, so we need to handle this
@@ skipping 140 matching lines @@
 }
 
 - (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
   return [dropTarget_ performDragOperation:sender view:self];
 }
 
 // Tons of stuff goes here, where we grab events going on in Cocoaland and send
 // them into the C++ system. TODO(avi): all that jazz
 
 @end