Pass gfx structs by const ref(gfx::Vector2D/F)

content/browser/android/overscroll_glow.h

 // Copyright (c) 2012 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_ANDROID_OVERSCROLL_GLOW_H_
 #define CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
@@ skipping 29 matching lines @@
   // The effect is enabled by default, but will remain dormant until the first
   // overscroll event.
   explicit OverscrollGlow(OverscrollGlowClient* client);
   ~OverscrollGlow();
 
   // Called when the root content layer overscrolls.
   // |accumulated_overscroll| and |overscroll_delta| are in device pixels, while
   // |velocity| is in device pixels / second.
   // Returns true if the effect still needs animation ticks.
   bool OnOverscrolled(base::TimeTicks current_time,
-                      gfx::Vector2dF accumulated_overscroll,
+                      const gfx::Vector2dF& accumulated_overscroll,
                       gfx::Vector2dF overscroll_delta,
                       gfx::Vector2dF velocity,
-                      gfx::Vector2dF overscroll_location);
+                      const gfx::Vector2dF& overscroll_location);
 
   // Returns true if the effect still needs animation ticks, with effect layers
   // attached to |parent_layer| if necessary.
   // Note: The effect will detach itself when no further animation is required.
   bool Animate(base::TimeTicks current_time, cc::Layer* parent_layer);
 
   // Update the effect according to the most recent display parameters,
   // Note: All dimensions are in device pixels.
   void OnFrameUpdated(const gfx::SizeF& viewport_size,
                       const gfx::SizeF& content_size,
@@ skipping 36 matching lines @@
   bool initialized_;
 
   scoped_refptr<cc::Layer> root_layer_;
 
   DISALLOW_COPY_AND_ASSIGN(OverscrollGlow);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_OVERSCROLL_GLOW_H_