Remove unreferenced content/browser/web_contents/web_contents_view_overscroll_ files.

content/browser/web_contents/web_contents_view_overscroll_animator_mac.h

-// Copyright 2014 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.
-
-#ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_
-#define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_
-
-#import <Cocoa/Cocoa.h>
-
-namespace content {
-class WebContentsImpl;
-
-// The direction of the overscroll animations. Backwards means that the user
-// wants to navigate backwards in the navigation history. The opposite applies
-// to forwards.
-enum OverscrollAnimatorDirection {
-  OVERSCROLL_ANIMATOR_DIRECTION_BACKWARDS,
-  OVERSCROLL_ANIMATOR_DIRECTION_FORWARDS,
-};
-}  // namespace content
-
-// NSViews that intend to manage the animation associated with an overscroll
-// must implement this protocol.
-@protocol WebContentsOverscrollAnimator
-// Some implementations require the WebContentsView to supply a snapshot of a
-// previous navigation state. This method determines whether the snapshot passed
-// to the overscroll animator is expected to be non-nil.
-- (BOOL)needsNavigationSnapshot;
-
-// Begin an overscroll animation. The method -needsNavigationSnapshot determines
-// whether |snapshot| can be nil.
-- (void)beginOverscrollInDirection:
-            (content::OverscrollAnimatorDirection)direction
-                navigationSnapshot:(NSImage*)snapshot;
-
-// Due to the nature of some of the overscroll animations, implementators of
-// this protocol must have control over the layout of the RenderWidgetHost's
-// NativeView. When there is no overscroll animation in progress, the
-// implementor must guarantee that the frame of the RenderWidgetHost's
-// NativeView in screen coordinates is the same as its own frame in screen
-// coordinates.
-// Due to the odd ownership cycles of the RenderWidgetHost's NativeView, it is
-// important that its presence in the NSView hierarchy is the only strong
-// reference, and that when it gets removed from the NSView hierarchy, it will
-// be dealloc'ed shortly thereafter.
-- (void)addRenderWidgetHostNativeView:(NSView*)view;
-
-// During an overscroll animation, |progress| ranges from 0 to 2, and indicates
-// how close the overscroll is to completing. If the overscroll ends with
-// |progress| >= 1, then the overscroll is considered completed.
-- (void)updateOverscrollProgress:(CGFloat)progress;
-
-// Animate the finish of the overscroll and perform a navigation. The navigation
-// may not happen synchronously, but is guaranteed to eventually occur.
-- (void)completeOverscroll:(content::WebContentsImpl*)webContents;
-
-// Animate the cancellation of the overscroll.
-- (void)cancelOverscroll;
-@end
-
-#endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_OVERSCROLL_ANIMATOR_MAC_H_