Minimize computeTotalInverse()'s inputs


The helper doesn't need a full context rec - it only looks at the CTM
and external local matrix.  Pass these explicitly instead.
Change-Id: I6a5884f65cd383c2df0e8d83c9086789bd96f345
Reviewed-on: https://skia-review.googlesource.com/15870
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 9ecc84e..0c8eacd 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -353,12 +353,7 @@
     const SkMatrix* localM) const
 {
     SkMatrix matrix;
-    if (!this->computeTotalInverse(ContextRec(paint,
-                                              ctm,
-                                              localM,
-                                              ContextRec::kPM4f_DstType, // doesn't matter here
-                                              dstCS),
-                                   &matrix)) {
+    if (!this->computeTotalInverse(ctm, localM, &matrix)) {
         return false;
     }