Migrate more functions from MathUtil to gfx::Transform

cc/software_renderer.cc

Index: cc/software_renderer.cc
diff --git a/cc/software_renderer.cc b/cc/software_renderer.cc
index 44e758d101b116e1e0b33738f71427e887435d99..398fb9e040bb0b0ddb1251830aa55e71368d1181 100644
--- a/cc/software_renderer.cc
+++ b/cc/software_renderer.cc
@@ -21,6 +21,7 @@
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/transform.h"
+#include "ui/gfx/transform_util.h"
 
 namespace cc {
 
@@ -183,7 +184,7 @@ void SoftwareRenderer::drawQuad(DrawingFrame& frame, const DrawQuad* quad)
     TRACE_EVENT0("cc", "SoftwareRenderer::drawQuad");
     gfx::Transform quadRectMatrix;
     quadRectTransform(&quadRectMatrix, quad->quadTransform(), quad->rect);
-    gfx::Transform contentsDeviceTransform = MathUtil::to2dTransform(frame.windowMatrix * frame.projectionMatrix * quadRectMatrix);
+    gfx::Transform contentsDeviceTransform = gfx::CreateFlattenedTransform(frame.windowMatrix * frame.projectionMatrix * quadRectMatrix);
     SkMatrix skDeviceMatrix;
     toSkMatrix(&skDeviceMatrix, contentsDeviceTransform);
     m_skCurrentCanvas->setMatrix(skDeviceMatrix);