RenderWidget popup should be a NSWindow so it can go outside the main window.

chrome/browser/chrome_browser_application_mac.h

Index: chrome/browser/chrome_browser_application_mac.h
diff --git a/chrome/browser/chrome_browser_application_mac.h b/chrome/browser/chrome_browser_application_mac.h
index 02c15588245e830c2e8e6e1e1167a243c40179ce..ac7da0e2e039c0c091843950119ba5dbc39dd5b2 100644
--- a/chrome/browser/chrome_browser_application_mac.h
+++ b/chrome/browser/chrome_browser_application_mac.h
@@ -15,21 +15,14 @@
 #import "base/memory/scoped_nsobject.h"
 #import "base/message_pump_mac.h"
 #include "base/synchronization/lock.h"
+#import "ui/base/cocoa/event_hook_application.h"
 
-// Event hooks must implement this protocol.
-@protocol CrApplicationEventHookProtocol
-- (void)hookForEvent:(NSEvent*)theEvent;
-@end
-
-@interface BrowserCrApplication : NSApplication<CrAppProtocol,
-                                                CrAppControlProtocol> {
+@interface BrowserCrApplication : CrEventHookApplication<CrAppProtocol,
+                                                         CrAppControlProtocol> {
  @private
   BOOL handlingSendEvent_;
   BOOL cyclingWindows_;
 
-  // Array of objects implementing CrApplicationEventHookProtocol.
-  scoped_nsobject<NSMutableArray> eventHooks_;
-
   // App's previous key windows. Most recent key window is last.
   // Does not include current key window. Elements of this vector are weak
   // references.
@@ -44,17 +37,6 @@
 // method cancels that process.
 - (void)cancelTerminate:(id)sender;
 
-// Add or remove an event hook to be called for every sendEvent:
-// that the application receives.  These handlers are called before
-// the normal [NSApplication sendEvent:] call is made.
-
-// This is not a good alternative to a nested event loop.  It should
-// be used only when normal event logic and notification breaks down
-// (e.g. when clicking outside a canBecomeKey:NO window to "switch
-// context" out of it).
-- (void)addEventHook:(id<CrApplicationEventHookProtocol>)hook;
-- (void)removeEventHook:(id<CrApplicationEventHookProtocol>)hook;
-
 // Keep track of the previous key windows and whether windows are being
 // cycled for use in determining whether a Panel window can become the
 // key window.