ui: Prefer +/- operators to apply offsets.

cc/math_util.cc

 // Copyright 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.
 
 #include "config.h"
 
 #include "cc/math_util.h"
 
 #include <cmath>
 #include <limits>
@@ skipping 92 matching lines @@
     numVerticesInClippedQuad++;
 }
 
 gfx::Rect MathUtil::mapClippedRect(const WebTransformationMatrix& transform, const gfx::Rect& srcRect)
 {
     return gfx::ToEnclosingRect(mapClippedRect(transform, gfx::RectF(srcRect)));
 }
 
 gfx::RectF MathUtil::mapClippedRect(const WebTransformationMatrix& transform, const gfx::RectF& srcRect)
 {
-    if (transform.isIdentityOrTranslation()) {
-        gfx::RectF mappedRect(srcRect);
-        mappedRect.Offset(static_cast<float>(transform.m41()), static_cast<float>(transform.m42()));
-        return mappedRect;
-    }
+    if (transform.isIdentityOrTranslation())
+        return srcRect + gfx::Vector2dF(static_cast<float>(transform.m41()), static_cast<float>(transform.m42()));
 
     // Apply the transform, but retain the result in homogeneous coordinates.
     gfx::QuadF q = gfx::QuadF(gfx::RectF(srcRect));
     HomogeneousCoordinate h1 = mapHomogeneousPoint(transform, gfx::Point3F(q.p1()));
     HomogeneousCoordinate h2 = mapHomogeneousPoint(transform, gfx::Point3F(q.p2()));
     HomogeneousCoordinate h3 = mapHomogeneousPoint(transform, gfx::Point3F(q.p3()));
     HomogeneousCoordinate h4 = mapHomogeneousPoint(transform, gfx::Point3F(q.p4()));
 
     return computeEnclosingClippedRect(h1, h2, h3, h4);
 }
@@ skipping 263 matching lines @@
     return static_cast<float>(Rad2Deg(std::acos(dotProduct)));
 }
 
 gfx::Vector2dF MathUtil::projectVector(gfx::Vector2dF source, gfx::Vector2dF destination)
 {
     float projectedLength = gfx::DotProduct(source, destination) / destination.LengthSquared();
     return gfx::Vector2dF(projectedLength * destination.x(), projectedLength * destination.y());
 }
 
 }  // namespace cc