Hook ScrollElasticityController to InputHandlerProxy

cc/input/scroll_elasticity_controller.h

+// Copyright 2014 The Chromium Authors. All rights reserved.

[aelias_OOO_until_Jul13, 2014/11/12 22:17:59]

This double license header is not a pattern used anywhere else, could you just
remove this and put the WebKit-style license at the top?  If you want to express
the fact that not all of the code originates from Apple anymore, the normal
pattern in WebKit licenses seems to be to add a second Copyright line, for
example see Source/core/css/CSSViewportRule.h

[ccameron, 2014/11/13 00:28:37]

The double license header pattern is used almost everywhere that a non-standard
license is needed in the chromium repository.

I copied the style from:
https://code.google.com/p/chromium/codesearch#chromium/src/ui/base/clipboard/...

See also :
content/browser/renderer_host/render_widget_host_view_mac.mm
content/browser/appcache/appcache_manifest_parser.cc
(and about 30 other files that come up if you do a git grep for "Apple Inc. All
rights reserved"
That example is from Webkit, this code is not in Webkit.

Some files put the 2 licenses next to each other, some embed the original
license next to the relevant code. I went with the second style, but am willing
to go with the first style.

Let me know if you have any other questions on this.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CC_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_
+#define CC_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_
+
+#include "base/time/time.h"
+#include "cc/base/cc_export.h"
+#include "ui/gfx/geometry/vector2d_f.h"
+
+namespace cc {
+
+class CC_EXPORT ScrollElasticityController {
+ public:
+  virtual void WillShutdown() = 0;

[jdduke (slow), 2014/11/12 20:13:37]

It's unfortunate to have yet another Bind/WillShutdown pairing. We could
probably achieve this implicitly with the existing
InputHandler/InputHandlerClient relationship (i.e., use the existing
InputHandlerProxy for WillShutdown/Animate routing), but maybe its' worth it to
be explicit here... Up to you.

[ccameron, 2014/11/13 00:28:37]

Agree -- pulled this through the existing InputHandlerProxy routing instead.

+  virtual void Animate(base::TimeTicks time) = 0;
+};
+
+// ScrollElasticityControllerClient is based on
+// WebKit/Source/platform/mac/ScrollElasticityController.h
+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+class CC_EXPORT ScrollElasticityControllerClient {
+ public:
+  virtual void BindToController(ScrollElasticityController* controller) = 0;
+  virtual bool AllowsHorizontalStretching() = 0;
+  virtual bool AllowsVerticalStretching() = 0;
+  // The amount that the view is stretched past the normal allowable bounds.
+  // The "overhang" amount.
+  virtual gfx::Vector2dF StretchAmount() = 0;
+  virtual bool PinnedInDirection(const gfx::Vector2dF& direction) = 0;
+  virtual bool CanScrollHorizontally() = 0;
+  virtual bool CanScrollVertically() = 0;
+
+  // Return the absolute scroll position, not relative to the scroll origin.
+  virtual gfx::Vector2dF AbsoluteScrollPosition() = 0;
+
+  virtual void ImmediateScrollBy(const gfx::Vector2dF& scroll) = 0;
+  virtual void ImmediateScrollByWithoutContentEdgeConstraints(
+      const gfx::Vector2dF& scroll) = 0;
+  virtual void StartSnapRubberbandTimer() = 0;
+  virtual void StopSnapRubberbandTimer() = 0;
+
+  // If the current scroll position is within the overhang area, this function
+  // will cause
+  // the page to scroll to the nearest boundary point.
+  virtual void AdjustScrollPositionToBoundsIfNecessary() = 0;
+};
+}  // namespace cc
+
+#endif  // CC_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_