A host of micro-optimizations and a refactor of TimeForBoundsToIntersect

I used perf to profile the compositor thread and addressed performance problems
with the top fuctions.  The result is about a 2.5x performance boost.
(~1.3ms -> ~.5ms) on List of Pokemon for UpdateTilePriorities.

Most of the optimizations are inlining small functions.  The refactor of
TimeForBoundsToIntersect also eliminates many unnecessary float-double
conversions.


BUG=172406
NOTRY=true


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=179770

Review URL: https://chromiumcodereview.appspot.com/12084031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@180229 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 14 insertions, 21 deletions

diff --git a/ui/gfx/rect_f.cc b/ui/gfx/rect_f.cc
index d7b1089..0f055e1 100644
--- a/ui/gfx/rect_f.cc
+++ b/ui/gfx/rect_f.cc
@@ -31,18 +31,6 @@ std::string RectF::ToString() const {
                             size().ToString().c_str());
 }
 
-RectF operator+(const RectF& lhs, const Vector2dF& rhs) {
-  RectF result(lhs);
-  result += rhs;
-  return result;
-}
-
-RectF operator-(const RectF& lhs, const Vector2dF& rhs) {
-  RectF result(lhs);
-  result -= rhs;
-  return result;
-}
-
 RectF IntersectRects(const RectF& a, const RectF& b) {
   RectF result = a;
   result.Intersect(b);
@@ -61,12 +49,6 @@ RectF SubtractRects(const RectF& a, const RectF& b) {
   return result;
 }
 
-RectF ScaleRect(const RectF& r, float x_scale, float y_scale) {
-  RectF result = r;
-  result.Scale(x_scale, y_scale);
-  return result;
-}
-
 RectF BoundingRect(const PointF& p1, const PointF& p2) {
   float rx = std::min(p1.x(), p2.x());
   float ry = std::min(p1.y(), p2.y());
diff --git a/ui/gfx/rect_f.h b/ui/gfx/rect_f.h
index 78524a0..62bedf2 100644
--- a/ui/gfx/rect_f.h
+++ b/ui/gfx/rect_f.h
@@ -69,8 +69,15 @@ inline bool operator!=(const RectF& lhs, const RectF& rhs) {
   return !(lhs == rhs);
 }
 
-UI_EXPORT RectF operator+(const RectF& lhs, const Vector2dF& rhs);
-UI_EXPORT RectF operator-(const RectF& lhs, const Vector2dF& rhs);
+inline RectF operator+(const RectF& lhs, const Vector2dF& rhs) {
+  return RectF(lhs.x() + rhs.x(), lhs.y() + rhs.y(),
+      lhs.width(), lhs.height());
+}
+
+inline RectF operator-(const RectF& lhs, const Vector2dF& rhs) {
+  return RectF(lhs.x() - rhs.x(), lhs.y() - rhs.y(),
+      lhs.width(), lhs.height());
+}
 
 inline RectF operator+(const Vector2dF& lhs, const RectF& rhs) {
   return rhs + lhs;
@@ -79,7 +86,11 @@ inline RectF operator+(const Vector2dF& lhs, const RectF& rhs) {
 UI_EXPORT RectF IntersectRects(const RectF& a, const RectF& b);
 UI_EXPORT RectF UnionRects(const RectF& a, const RectF& b);
 UI_EXPORT RectF SubtractRects(const RectF& a, const RectF& b);
-UI_EXPORT RectF ScaleRect(const RectF& r, float x_scale, float y_scale);
+
+inline RectF ScaleRect(const RectF& r, float x_scale, float y_scale) {
+  return RectF(r.x() * x_scale, r.y() * y_scale,
+       r.width() * x_scale, r.height() * y_scale);
+}
 
 inline RectF ScaleRect(const RectF& r, float scale) {
   return ScaleRect(r, scale, scale);