[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/base/region.cc

Index: cc/base/region.cc
diff --git a/cc/base/region.cc b/cc/base/region.cc
index 1cda32d3ba2d01d53235b474246a32fa95713b72..45e70f0a42364af5956ae9900d2e76887df42103 100644
--- a/cc/base/region.cc
+++ b/cc/base/region.cc
@@ -14,14 +14,14 @@ Region::Region(const Region& region)
     : skregion_(region.skregion_) {
 }
 
-Region::Region(gfx::Rect rect)
+Region::Region(const gfx::Rect& rect)
     : skregion_(gfx::RectToSkIRect(rect)) {
 }
 
 Region::~Region() {
 }
 
-const Region& Region::operator=(gfx::Rect rect) {
+const Region& Region::operator=(const gfx::Rect& rect) {
   skregion_ = SkRegion(gfx::RectToSkIRect(rect));
   return *this;
 }
@@ -51,7 +51,7 @@ bool Region::Contains(gfx::Point point) const {
   return skregion_.contains(point.x(), point.y());
 }
 
-bool Region::Contains(gfx::Rect rect) const {
+bool Region::Contains(const gfx::Rect& rect) const {
   if (rect.IsEmpty())
     return true;
   return skregion_.contains(gfx::RectToSkIRect(rect));
@@ -63,7 +63,7 @@ bool Region::Contains(const Region& region) const {
   return skregion_.contains(region.skregion_);
 }
 
-bool Region::Intersects(gfx::Rect rect) const {
+bool Region::Intersects(const gfx::Rect& rect) const {
   return skregion_.intersects(gfx::RectToSkIRect(rect));
 }