Added GrAAFlatteningConvexPathRenderer.

This is an alternate version of GrAAConvexPathRenderer which handles
curves by first flattening them to straight lines.

BUG=skia:

Review URL: https://codereview.chromium.org/1158803002
diff --git a/src/gpu/GrAALinearizingConvexPathRenderer.h b/src/gpu/GrAALinearizingConvexPathRenderer.h
new file mode 100644
index 0000000..8776332
--- /dev/null
+++ b/src/gpu/GrAALinearizingConvexPathRenderer.h
@@ -0,0 +1,35 @@
+
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrAALinearizingConvexPathRenderer_DEFINED
+#define GrAALinearizingConvexPathRenderer_DEFINED
+
+#include "GrPathRenderer.h"
+
+class GrAALinearizingConvexPathRenderer : public GrPathRenderer {
+public:
+    GrAALinearizingConvexPathRenderer();
+
+    virtual bool canDrawPath(const GrDrawTarget*,
+                             const GrPipelineBuilder*,
+                             const SkMatrix& viewMatrix,
+                             const SkPath&,
+                             const GrStrokeInfo&,
+                             bool antiAlias) const override;
+
+protected:
+    virtual bool onDrawPath(GrDrawTarget*,
+                            GrPipelineBuilder*,
+                            GrColor,
+                            const SkMatrix& viewMatrix,
+                            const SkPath&,
+                            const GrStrokeInfo&,
+                            bool antiAlias) override;
+};
+
+#endif