Add support for skew()

Change-Id: Ia3a9a867f74fd78b61f75179e3788fdc2f0cacd0
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 16a1de7..2067acc1 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -766,6 +766,10 @@
     mSnapshot->transform->scale(sx, sy, 1.0f);
 }
 
+void OpenGLRenderer::skew(float sx, float sy) {
+    mSnapshot->transform->skew(sx, sy);
+}
+
 void OpenGLRenderer::setMatrix(SkMatrix* matrix) {
     mSnapshot->transform->load(*matrix);
 }