cc: Apply the layer's initial CSS scale to the contentsScale to render text at the right resolution.

cc/math_util.cc

Index: cc/math_util.cc
diff --git a/cc/math_util.cc b/cc/math_util.cc
index d90eb090abef6fbc004f87cedc0a3188419486cf..8cb7d2b70eeeccf42fbeae11fed6b5cd56e0018b 100644
--- a/cc/math_util.cc
+++ b/cc/math_util.cc
@@ -9,6 +9,7 @@
 #include "FloatPoint.h"
 #include "FloatQuad.h"
 #include "IntRect.h"
+#include <cmath>
 #include <public/WebTransformationMatrix.h>
 
 using WebKit::WebTransformationMatrix;
@@ -361,6 +362,20 @@ void CCMathUtil::flattenTransformTo2d(WebTransformationMatrix& transform)
     transform.setM43(0);
 }
 
+static inline float scaleOnAxis(double a, double b, double c)
+{
+    return std::sqrt(a * a + b * b + c * c);
+}
+
+FloatPoint CCMathUtil::computeTransform2dScaleComponents(const WebTransformationMatrix& transform)
+{
+    if (transform.hasPerspective())
+        return FloatPoint(1, 1);
+    float xScale = scaleOnAxis(transform.m11(), transform.m12(), transform.m13());
+    float yScale = scaleOnAxis(transform.m21(), transform.m22(), transform.m23());
+    return FloatPoint(xScale, yScale);
+}
+
 float CCMathUtil::smallestAngleBetweenVectors(const FloatSize& v1, const FloatSize& v2)
 {
     float dotProduct = (v1.width() * v2.width() + v1.height() * v2.height()) / (v1.diagonalLength() * v2.diagonalLength());