Add a keyboard shortcut on Escape that emits the IDC_STOP command....

chrome/browser/cocoa/chrome_event_processing_window.mm

 // Copyright (c) 2009 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 "chrome/browser/cocoa/chrome_event_processing_window.h"
 
 #include "base/logging.h"
 #import "chrome/browser/cocoa/browser_command_executor.h"
 #import "chrome/browser/cocoa/browser_frame_view.h"
 #import "chrome/browser/cocoa/tab_strip_controller.h"
@@ skipping 26 matching lines @@
     return YES;
   }
   return NO;
 }
 
 - (BOOL)handleExtraWindowKeyboardShortcut:(NSEvent*)event {
   return [self handleExtraKeyboardShortcut:event
                                  fromTable:CommandForWindowKeyboardShortcut];
 }
 
+- (BOOL)handleDelayedWindowKeyboardShortcut:(NSEvent*)event {
+  return [self handleExtraKeyboardShortcut:event
+                         fromTable:CommandForDelayedWindowKeyboardShortcut];
+}
+
 - (BOOL)handleExtraBrowserKeyboardShortcut:(NSEvent*)event {
   return [self handleExtraKeyboardShortcut:event
                                  fromTable:CommandForBrowserKeyboardShortcut];
 }
 
 - (BOOL)performKeyEquivalent:(NSEvent*)event {
   if (redispatchingEvent_)
     return NO;
 
   // Give the web site a chance to handle the event. If it doesn't want to
   // handle it, it will call us back with one of the |handle*| methods above.
   NSResponder* r = [self firstResponder];
   if ([r isKindOfClass:[RenderWidgetHostViewCocoa class]])
     return [r performKeyEquivalent:event];
 
   // Handle per-window shortcuts like cmd-1, but do not handle browser-level
   // shortcuts like cmd-left (else, cmd-left would do history navigation even
   // if e.g. the Omnibox has focus).
   if ([self handleExtraWindowKeyboardShortcut:event])
     return YES;
-  return [super performKeyEquivalent:event];
+
+  if ([super performKeyEquivalent:event])
+    return YES;
+
+  // Handle per-window shortcuts like Esc after giving everybody else a chance
+  // to handle them
+  return [self handleDelayedWindowKeyboardShortcut:event];
 }
 
 - (BOOL)redispatchEvent:(NSEvent*)event {
   DCHECK(event);
   DCHECK_EQ([event window], self);
   eventHandled_ = YES;
   redispatchingEvent_ = YES;
   [NSApp sendEvent:event];
   redispatchingEvent_ = NO;
 
   // If the event was not handled by [NSApp sendEvent:], the sendEvent:
   // method below will be called, and because |redispatchingEvent_| is YES,
   // |eventHandled_| will be set to NO.
   return eventHandled_;
 }
 
 - (void)sendEvent:(NSEvent*)event {
   if (!redispatchingEvent_)
     [super sendEvent:event];
   else
     eventHandled_ = NO;
 }
 
 @end  // ChromeEventProcessingWindow