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

content/browser/android/overscroll_glow.h

Index: content/browser/android/overscroll_glow.h
diff --git a/content/browser/android/overscroll_glow.h b/content/browser/android/overscroll_glow.h
index 6ae45dde4acaa415dd9d2784e3e20d8ea8506a77..8fae95c4b86704939d5e9d72fe8996f9ab6ef1dc 100644
--- a/content/browser/android/overscroll_glow.h
+++ b/content/browser/android/overscroll_glow.h
@@ -47,10 +47,10 @@ class OverscrollGlow {
   // |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.