Provide gtest printers for ui/gfx geometry types

ui/gfx/transform.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_TRANSFORM_H_
 #define UI_GFX_TRANSFORM_H_
 
+#include <iosfwd>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "third_party/skia/include/utils/SkMatrix44.h"
 #include "ui/gfx/gfx_export.h"
 #include "ui/gfx/vector2d_f.h"
 
 namespace gfx {
 
 class BoxF;
@@ skipping 243 matching lines @@
                               Point* point) const;
 
   void TransformPointInternal(const SkMatrix44& xform,
                               Point3F* point) const;
 
   SkMatrix44 matrix_;
 
   // copy/assign are allowed.
 };
 
+// This is declared here for use in gtest-based unit tests but is defined in
+// the gfx_test_support target. Depend on that to use this in your unit test.
+// This should not be used in production code - call ToString() instead.
+void PrintTo(const Transform& transform, ::std::ostream* os);
+
 }  // namespace gfx
 
 #endif  // UI_GFX_TRANSFORM_H_