Make scroll offset type of float in cc

ui/gfx/geometry/scroll_offset.h

Index: ui/gfx/geometry/scroll_offset.h
diff --git a/ui/gfx/geometry/scroll_offset.h b/ui/gfx/geometry/scroll_offset.h
new file mode 100644
index 0000000000000000000000000000000000000000..f00a7a406ab9f7cffa9e430c5c684fd3bd28418d
--- /dev/null
+++ b/ui/gfx/geometry/scroll_offset.h
@@ -0,0 +1,80 @@
+// 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 UI_GFX_GEOMETRY_SCROLL_OFFSET_H_
+#define UI_GFX_GEOMETRY_SCROLL_OFFSET_H_
+
+#include "ui/gfx/geometry/safe_integer_conversions.h"
+#include "ui/gfx/geometry/vector2d.h"
+#include "ui/gfx/gfx_export.h"
+
+namespace gfx {
+
+class GFX_EXPORT ScrollOffset {
+ public:
+  ScrollOffset() : x_(0), y_(0) {}
+  ScrollOffset(double x, double y) : x_(x), y_(y) {}
+
+  double x() const { return x_; }
+  void set_x(double x) { x_ = x; }
+
+  double y() const { return y_; }
+  void set_y(double y) { y_ = y; }
+
+  // True if both components are 0.
+  bool IsZero() const;
+
+  // Add the components of the |other| ScrollOffset to the current ScrollOffset.
+  void Add(const ScrollOffset& other);
+  // Subtract the components of the |other| ScrollOffset from the current
+  // ScrollOffset.
+  void Subtract(const ScrollOffset& other);
+
+  void operator+=(const ScrollOffset& other) { Add(other); }
+  void operator-=(const ScrollOffset& other) { Subtract(other); }
+
+ private:
+  double x_;
+  double y_;
+};
+
+inline bool operator==(const ScrollOffset& lhs, const ScrollOffset& rhs) {
+  return lhs.x() == rhs.x() && lhs.y() == rhs.y();
+}
+
+inline bool operator!=(const ScrollOffset& lhs, const ScrollOffset& rhs) {
+  return lhs.x() != rhs.x() || lhs.y() != rhs.y();
+}
+
+inline ScrollOffset operator-(const ScrollOffset& v) {
+  return ScrollOffset(-v.x(), -v.y());
+}
+
+inline ScrollOffset operator+(const ScrollOffset& lhs,
+                              const ScrollOffset& rhs) {
+  ScrollOffset result = lhs;
+  result.Add(rhs);
+  return result;
+}
+
+inline ScrollOffset operator-(const ScrollOffset& lhs,
+                              const ScrollOffset& rhs) {
+  ScrollOffset result = lhs;
+  result.Add(-rhs);
+  return result;
+}
+
+inline Vector2d ToFlooredVector2d(const ScrollOffset& v) {

[danakj, 2014/09/25 15:13:31]

make this a member 

[Yufeng Shen (Slow to review), 2014/09/25 20:06:24]

Done.

+  int x = ToFlooredInt(v.x());
+  int y = ToFlooredInt(v.y());
+  return Vector2d(x, y);
+}
+
+inline Vector2dF ToVector2dF(const ScrollOffset& v) {

[danakj, 2014/09/25 15:13:31]

make a member

[Yufeng Shen (Slow to review), 2014/09/25 20:06:24]

Done.

+  return Vector2dF(v.x(), v.y());
+}
+
+}  // namespace gfx
+
+#endif  // UI_GFX_GEOMETRY_SCROLL_OFFSET_H_