Add platform/transforms pretty printers for logging and testing

third_party/WebKit/Source/platform/transforms/AffineTransformTest.cpp

+// Copyright 2016 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.
+
+#include "platform/transforms/AffineTransform.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "wtf/text/WTFString.h"
+
+namespace blink {
+
+TEST(AffineTransformTest, ToString)
+{
+    AffineTransform identity;
+    EXPECT_EQ(String("identity"), identity.toString());

[jbroman, 2016/08/21 16:21:07]

nit: You shouldn't need the String() wrapper on the expected values.

[pdr., 2016/08/22 17:27:35]

Done. I should remove these from the other tests in
https://codereview.chromium.org/2191233002 as well, but lets do that as a
followup.

+    EXPECT_EQ(String("[1,0,0,\n0,1,0]"), identity.toString(true));
+
+    AffineTransform translation = AffineTransform::translation(7, 9);
+    EXPECT_EQ(String("translation(7,9)"), translation.toString());
+    EXPECT_EQ(String("[1,0,7,\n0,1,9]"), translation.toString(true));
+
+    AffineTransform rotation;
+    rotation.rotate(180);
+    EXPECT_EQ(String("translation(0,0), scale(1,1), angle(3.14159rad), remainder(1,0,0,1)"), rotation.toString());
+    EXPECT_EQ(String("[-1,-1.22465e-16,0,\n1.22465e-16,-1,0]"), rotation.toString(true));
+
+    AffineTransform columnMajorConstructor(1, 4, 2, 5, 3, 6);
+    EXPECT_EQ(String("[1,2,3,\n4,5,6]"), columnMajorConstructor.toString(true));
+}
+
+} // namespace blink