Make scroll offset type of float in cc

ui/gfx/geometry/scroll_offset.cc

Index: ui/gfx/geometry/scroll_offset.cc
diff --git a/ui/gfx/geometry/scroll_offset.cc b/ui/gfx/geometry/scroll_offset.cc
new file mode 100644
index 0000000000000000000000000000000000000000..297997db9a0547b553afd28fe727049fb8de2f86
--- /dev/null
+++ b/ui/gfx/geometry/scroll_offset.cc
@@ -0,0 +1,23 @@
+// 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.
+
+#include "ui/gfx/geometry/scroll_offset.h"
+
+namespace gfx {
+
+bool ScrollOffset::IsZero() const {
+  return x_ == 0 && y_ == 0;
+}
+
+void ScrollOffset::Add(const ScrollOffset& other) {
+  x_ += other.x_;
+  y_ += other.y_;
+}
+
+void ScrollOffset::Subtract(const ScrollOffset& other) {
+  x_ -= other.x_;
+  y_ -= other.y_;
+}
+
+}  // namespace gfx