Move page scale ownership to LayerTreeImpl.

cc/pinch_zoom_viewport.h

-// Copyright 2013 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 CC_PINCH_ZOOM_VIEWPORT_H_
-#define CC_PINCH_ZOOM_VIEWPORT_H_
-
-#include "cc/cc_export.h"
-#include "ui/gfx/rect.h"
-#include "ui/gfx/transform.h"
-
-namespace cc {
-
-class CC_EXPORT PinchZoomViewport {
- public:
-  PinchZoomViewport();
-
-  float total_page_scale_factor() const {
-    return page_scale_factor_ * page_scale_delta_;
-  }
-
-  void set_page_scale_factor(float factor) { page_scale_factor_ = factor; }
-  float page_scale_factor() const { return page_scale_factor_; }
-
-  void set_page_scale_delta(float delta);
-  float page_scale_delta() const  { return page_scale_delta_; }
-
-  float min_page_scale_factor() const { return min_page_scale_factor_; }
-  float max_page_scale_factor() const { return max_page_scale_factor_; }
-
-  void set_sent_page_scale_delta(float delta) {
-    sent_page_scale_delta_ = delta;
-  }
-
-  float sent_page_scale_delta() const { return sent_page_scale_delta_; }
-
-  void set_device_scale_factor(float factor) { device_scale_factor_ = factor; }
-  float device_scale_factor() const { return device_scale_factor_; }
-
-  // Returns true if the passed parameters were different from those previously
-  // cached.
-  bool SetPageScaleFactorAndLimits(float page_scale_factor,
-                                   float min_page_scale_factor,
-                                   float max_page_scale_factor);
-
-  void set_layout_viewport_size(const gfx::SizeF& size) {
-    layout_viewport_size_ = size;
-  }
-  // We need to store device_viewport_size separately because in mobile
-  // fixed-layout mode, there is not necessarily a simple mapping between layout
-  // viewport size and device viewport size.
-  void set_device_viewport_size(const gfx::SizeF& size) {
-    device_viewport_size_ = size;
-  }
-
-  // The implTransform applies the page scale transformation.
-  //
-  // implTransform = S[pageScaleFactor] * S[pageScaleDelta]
-  gfx::Transform ImplTransform(bool page_scale_pinch_zoom_enabled) const;
-
- private:
-  float page_scale_factor_;
-  float page_scale_delta_;
-  float sent_page_scale_delta_;
-  float max_page_scale_factor_;
-  float min_page_scale_factor_;
-  float device_scale_factor_;
-
-  gfx::SizeF layout_viewport_size_;
-  gfx::SizeF device_viewport_size_;
-};
-
-}  // namespace cc
-
-#endif  // CC_PINCH_ZOOM_VIEWPORT_H_