Mac: Fix SDK 10.11 Compile errors after clang roll in r387792

chrome/browser/ui/cocoa/tabs/tab_window_controller.mm

 // Copyright (c) 2012 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/ui/cocoa/tabs/tab_window_controller.h"
 
 #include "base/logging.h"
 #import "base/mac/sdk_forward_declarations.h"
 #import "chrome/browser/ui/cocoa/browser_window_layout.h"
 #import "chrome/browser/ui/cocoa/fast_resize_view.h"
@@ skipping 15 matching lines @@
 // of non-layer backed content like the window controls.
 - (void)insertTabStripBackgroundViewIntoWindow:(NSWindow*)window;
 @end
 
 @interface TabWindowOverlayWindow : NSWindow
 @end
 
 @implementation TabWindowOverlayWindow
 
 - (const ui::ThemeProvider*)themeProvider {
-  if ([self parentWindow])
-    return [[[self parentWindow] windowController] themeProvider];
-  return NULL;
+  return [[self parentWindow] themeProvider];
 }
 
 - (ThemedWindowStyle)themedWindowStyle {
-  if ([self parentWindow])
-    return [[[self parentWindow] windowController] themedWindowStyle];
-  return NO;
+  return [[self parentWindow] themedWindowStyle];
 }
 
 - (NSPoint)themeImagePositionForAlignment:(ThemeImageAlignment)alignment {
-  if ([self parentWindow]) {
-    return [[[self parentWindow] windowController]
-        themeImagePositionForAlignment:alignment];
-  }
-  return NSZeroPoint;
+  return [[self parentWindow] themeImagePositionForAlignment:alignment];
 }
 
 @end
 
 @implementation TabWindowController
 
 - (id)initTabWindowControllerWithTabStrip:(BOOL)hasTabStrip {
   const CGFloat kDefaultWidth = 750;
   const CGFloat kDefaultHeight = 600;
 
@@ skipping 328 matching lines @@
   [visualEffectView addSubview:tabStripBackgroundView_];
 }
 
 // Called when the size of the window content area has changed. Override to
 // position specific views. Base class implementation does nothing.
 - (void)layoutSubviews {
   NOTIMPLEMENTED();
 }
 
 @end