Make WebKitCSSMatrix an alias of DOMMatrix

third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp

Index: third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp b/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp
index e4c1ed95915423ee26b242a647d136df8fafd511..acd9bff3e1562b60bb72ebdd0f6cab4bba46ae33 100644
--- a/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp
@@ -300,20 +300,16 @@ DOMFloat64Array* DOMMatrixReadOnly::toFloat64Array() const {
 }
 
 const String DOMMatrixReadOnly::toString() const {
-  std::stringstream stream;
   if (is2D()) {
-    stream << "matrix(" << a() << ", " << b() << ", " << c() << ", " << d()
-           << ", " << e() << ", " << f();
+    return String::format("matrix(%f, %f, %f, %f, %f, %f)", a(), b(), c(), d(),

[foolip, 2017/03/21 08:47:30]

Is this a drive-by change, or does it affect the output in  any case?

[Byoungkwon Ko, 2017/04/26 01:31:35]

yes, when we were using steam, we should fix decimal fraction part for float
variable.
So I changed to string::format.
Is it better to use precision() ???

[foolip, 2017/04/26 07:29:19]

Hmm, this is actually related to https://github.com/w3c/fxtf-drafts/issues/120.
Should double precision be used here?

In any case, I would suggest doing this change separately.

+                          e(), f());
   } else {
-    stream << "matrix3d(" << m11() << ", " << m12() << ", " << m13() << ", "
-           << m14() << ", " << m21() << ", " << m22() << ", " << m23() << ", "
-           << m24() << ", " << m31() << ", " << m32() << ", " << m33() << ", "
-           << m34() << ", " << m41() << ", " << m42() << ", " << m43() << ", "
-           << m44();
+    return String::format(
+        "matrix3d(%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, "
+        "%f)",
+        m11(), m12(), m13(), m14(), m21(), m22(), m23(), m24(), m31(), m32(),
+        m33(), m34(), m41(), m42(), m43(), m44());
   }
-  stream << ")";
-
-  return String(stream.str().c_str());
 }
 
 ScriptValue DOMMatrixReadOnly::toJSONForBinding(