Make GrMatrix an alias of SkMatrix. Add new methods to SkMatrix.

Review URL: http://codereview.appspot.com/4538043/

Checked in on behalf of reed@ with some additional work (remove the do-nother sk->gr matrix converter).



git-svn-id: http://skia.googlecode.com/svn/trunk@1289 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrContext.cpp b/gpu/src/GrContext.cpp
index 8461187..2d93e4b 100644
--- a/gpu/src/GrContext.cpp
+++ b/gpu/src/GrContext.cpp
@@ -925,7 +925,7 @@
             GrVec strokeSize;;
             if (width > 0) {
                 strokeSize.set(width, width);
-                combinedMatrix.mapVec(&strokeSize);
+                combinedMatrix.mapVectors(&strokeSize, 1);
                 strokeSize.setAbs(strokeSize);
             } else {
                 strokeSize.set(GR_Scalar1, GR_Scalar1);