Turn off Auto Layout pending investigation of a performance regression.

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 58 matching lines @@
 
 @implementation ChromeContentView
 
 // NSView overrides.
 
 // Since Auto Layout and frame-based layout behave differently in small but
 // important ways (e.g. Auto Layout can restrict window resizing, frame-based
 // layout doesn't log a warning when a view's autoresizing mask can't be
 // maintained), ensure that it's on instead of letting it depend on content.
 + (BOOL)requiresConstraintBasedLayout {
-  return YES;
+  // TODO(sdy): Turn back on (or remove) after investigating a performance
+  // regression: https://crbug.com/706931
+  return NO;
 }
 
 @end
 
 @implementation TabWindowController
 
 - (id)initTabWindowControllerWithTabStrip:(BOOL)hasTabStrip
                                  titleBar:(BOOL)hasTitleBar {
   const CGFloat kDefaultWidth = 750;
   const CGFloat kDefaultHeight = 600;
@@ skipping 388 matching lines @@
 
 - (void)windowWillEnterFullScreenNotification:(NSNotification*)notification {
   [[visualEffectView_ animator] setAlphaValue:0.0];
 }
 
 - (void)windowWillExitFullScreenNotification:(NSNotification*)notification {
   [[visualEffectView_ animator] setAlphaValue:1.0];
 }
 
 @end