Pass gfx::Rect and gfx::RectF by const ref.

Avoid unneccessary copy of structures gfx::Rect & gfx::RectF 
by passing them by const ref rather than value. 

Any struct of size > 4 bytes should be passed by const ref. 
Passing by ref for these structs is faster than passing 
by value, especially when invoking function has multiple parameters. 

Pass by value creates unneccessary overhead which should be avoided.

BUG=159273

Review URL: https://codereview.chromium.org/93663004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244224 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 18 insertions, 10 deletions

diff --git a/cc/layers/scrollbar_theme_painter.h b/cc/layers/scrollbar_theme_painter.h
index f7553ac..8f3e68d 100644
--- a/cc/layers/scrollbar_theme_painter.h
+++ b/cc/layers/scrollbar_theme_painter.h
@@ -19,16 +19,24 @@ class CC_EXPORT ScrollbarThemePainter {
  public:
   virtual ~ScrollbarThemePainter() {}
 
-  virtual void PaintScrollbarBackground(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintTrackBackground(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintBackTrackPart(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintForwardTrackPart(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintBackButtonStart(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintBackButtonEnd(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintForwardButtonStart(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintForwardButtonEnd(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintTickmarks(SkCanvas* canvas, gfx::Rect rect) = 0;
-  virtual void PaintThumb(SkCanvas* canvas, gfx::Rect rect) = 0;
+  virtual void PaintScrollbarBackground(SkCanvas* canvas,
+                                        const gfx::Rect& rect) = 0;
+  virtual void PaintTrackBackground(SkCanvas* canvas,
+                                    const gfx::Rect& rect) = 0;
+  virtual void PaintBackTrackPart(SkCanvas* canvas,
+                                  const gfx::Rect& rect) = 0;
+  virtual void PaintForwardTrackPart(SkCanvas* canvas,
+                                     const gfx::Rect& rect) = 0;
+  virtual void PaintBackButtonStart(SkCanvas* canvas,
+                                    const gfx::Rect& rect) = 0;
+  virtual void PaintBackButtonEnd(SkCanvas* canvas,
+                                  const gfx::Rect& rect) = 0;
+  virtual void PaintForwardButtonStart(SkCanvas* canvas,
+                                       const gfx::Rect& rect) = 0;
+  virtual void PaintForwardButtonEnd(SkCanvas* canvas,
+                                     const gfx::Rect& rect) = 0;
+  virtual void PaintTickmarks(SkCanvas* canvas, const gfx::Rect& rect) = 0;
+  virtual void PaintThumb(SkCanvas* canvas, const gfx::Rect& rect) = 0;
 };
 
 }  // namespace cc