Implement translate() and translateSelf() in DOMMatrix.

Source/core/dom/DOMMatrixReadOnly.cpp

Index: Source/core/dom/DOMMatrixReadOnly.cpp
diff --git a/Source/core/dom/DOMMatrixReadOnly.cpp b/Source/core/dom/DOMMatrixReadOnly.cpp
index 887e75fa11d33f6e28a95ce6cd9b86bc1ddceb4e..b722356ed19148fc5f5199c2fb7ae4f3552f427e 100644
--- a/Source/core/dom/DOMMatrixReadOnly.cpp
+++ b/Source/core/dom/DOMMatrixReadOnly.cpp
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "config.h"
-#include "core/dom/DOMMatrixReadOnly.h"
+#include "core/dom/DOMMatrix.h"
 
 namespace blink {
 
@@ -20,4 +20,9 @@ bool DOMMatrixReadOnly::isIdentity() const
         && m14() == 0 && m24() == 0 && m34() == 0 && m44() == 1;
 }
 
+DOMMatrix* DOMMatrixReadOnly::translate(double tx, double ty, double tz)
+{
+    return DOMMatrix::create(this)->translateSelf(tx, ty, tz);
+}
+
 } // namespace blink