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

chrome/browser/ui/cocoa/animatable_image.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/ui/cocoa/animatable_image.h"
 
 #include "base/logging.h"
+#import "base/mac/sdk_forward_declarations.h"
 #import "third_party/google_toolbox_for_mac/src/AppKit/GTMNSAnimation+Duration.h"
 
+@interface AnimatableImage (Private) <CAAnimationDelegate>
+@end
+
 @implementation AnimatableImage
 
 @synthesize startFrame = startFrame_;
 @synthesize endFrame = endFrame_;
 @synthesize startOpacity = startOpacity_;
 @synthesize endOpacity = endOpacity_;
 @synthesize duration = duration_;
 
 - (id)initWithImage:(NSImage*)image
      animationFrame:(NSRect)animationFrame {
@@ skipping 94 matching lines @@
   [CATransaction setValue:[NSNumber numberWithFloat:[self duration]]
                    forKey:kCATransactionAnimationDuration];
   if (boundsAnimation) {
     [layer addAnimation:boundsAnimation forKey:@"bounds"];
   }
   [layer addAnimation:positionAnimation forKey:@"position"];
   [layer addAnimation:opacityAnimation forKey:@"opacity"];
   [CATransaction commit];
 }
 
+- (void)animationDidStart:(CAAnimation*)animation {
+}
+
 // CAAnimation delegate method called when the animation is complete.
 - (void)animationDidStop:(CAAnimation*)animation finished:(BOOL)flag {
   // Close the window, releasing self.
   [self close];
 }
 
 @end