Fix OSX 10.12 compilation errors in chrome/browser/ui.

chrome/browser/ui/cocoa/spinner_view.mm

 // Copyright 2015 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/spinner_view.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 13 matching lines @@
 const CGFloat kArcLength               = 58.9;
 const CGFloat kArcStrokeWidth          = 3.0;
 const CGFloat kArcAnimationTime        = 1.333;
 const CGFloat kArcStartAngle           = kDegrees180;
 const CGFloat kArcEndAngle             = (kArcStartAngle + kDegrees270);
 const CGFloat kRotationTime            = 1.56863;
 NSString* const kSpinnerAnimationName  = @"SpinnerAnimationName";
 NSString* const kRotationAnimationName = @"RotationAnimationName";
 }
 
-@interface SpinnerView () {
+@interface SpinnerView () <CALayerDelegate> {
   base::scoped_nsobject<CAAnimationGroup> spinnerAnimation_;
   base::scoped_nsobject<CABasicAnimation> rotationAnimation_;
   CAShapeLayer* shapeLayer_;  // Weak.
   CALayer* rotationLayer_;  // Weak.
 }
 @end
 
 
 @implementation SpinnerView
 
@@ skipping 248 matching lines @@
       [rotationLayer_ addAnimation:rotationAnimation_.get()
                             forKey:kRotationAnimationName];
     }
   } else {
     [shapeLayer_ removeAllAnimations];
     [rotationLayer_ removeAllAnimations];
   }
 }
 
 @end