Theme delegate fixes for the 10.6 SDK folllowing r43708....

chrome/browser/cocoa/fullscreen_window.mm

 // Copyright (c) 2010 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/fullscreen_window.h"
 
 #include "base/mac_util.h"
 #include "chrome/browser/browser_theme_provider.h"
 #import "chrome/browser/cocoa/themed_window.h"
 
@@ skipping 65 matching lines @@
 
   // Explicitly enable |-performClose:| (see above); otherwise the fact that
   // this window does not have a close button results in it being disabled.
   if (action == @selector(performClose:))
     return YES;
 
   return [super validateUserInterfaceItem:item];
 }
 
 - (ThemeProvider*)themeProvider {
-  return [[self delegate] themeProvider];
+  id delegate = [self delegate];
+  if (![delegate respondsToSelector:@selector(themeProvider)])
+    return NULL;
+  return [delegate themeProvider];
 }
 
 - (ThemedWindowStyle)themedWindowStyle {
-  return [[self delegate] themedWindowStyle];
+  id delegate = [self delegate];
+  if (![delegate respondsToSelector:@selector(themedWindowStyle)])
+    return THEMED_NORMAL;
+  return [delegate themedWindowStyle];
 }
 
 - (NSPoint)themePatternPhase {
-  return [[self delegate] themePatternPhase];
+  id delegate = [self delegate];
+  if (![delegate respondsToSelector:@selector(themePatternPhase)])
+    return NSMakePoint(0, 0);
+  return [delegate themePatternPhase];
 }
 
 @end