Avoid unnecessary sqrt calls in ComputeTransform2dScaleComponents.

cc/base/math_util.cc

Index: cc/base/math_util.cc
diff --git a/cc/base/math_util.cc b/cc/base/math_util.cc
index eeb1523db46a080aff9850caaf126c1c3f8b0509..76b2bb93cc325f0dd77fa35090ba5230c9dbbd6a 100644
--- a/cc/base/math_util.cc
+++ b/cc/base/math_util.cc
@@ -466,6 +466,13 @@ gfx::RectF MathUtil::ScaleRectProportional(const gfx::RectF& input_outer_rect,
 }
 
 static inline float ScaleOnAxis(double a, double b, double c) {
+  if (!b && !c)
+    return a;
+  if (!a && !c)
+    return b;
+  if (!a && !b)
+    return c;
+
   // Do the sqrt as a double to not lose precision.
   return static_cast<float>(std::sqrt(a * a + b * b + c * c));
 }