Implement rotate*() methods in DOMMatrix.

Source/core/dom/DOMMatrixReadOnly.idl

Index: Source/core/dom/DOMMatrixReadOnly.idl
diff --git a/Source/core/dom/DOMMatrixReadOnly.idl b/Source/core/dom/DOMMatrixReadOnly.idl
index cb91b5b61a94092d6deb5a16ce25090988e53f35..730bf941c10b38767314fbc0a9b242723827dad7 100644
--- a/Source/core/dom/DOMMatrixReadOnly.idl
+++ b/Source/core/dom/DOMMatrixReadOnly.idl
@@ -53,6 +53,16 @@
                               optional unrestricted double ox = 0,
                               optional unrestricted double oy = 0,
                               optional unrestricted double oz = 0);
+    DOMMatrix rotate(unrestricted double angle,
+                     optional unrestricted double ox = 0,
+                     optional unrestricted double oy = 0);
+    DOMMatrix rotateFromVector(unrestricted double x,
+                               unrestricted double y);
+    DOMMatrix rotateAxisAngle(unrestricted double x,
+                              unrestricted double y,
+                              unrestricted double z,
+                              unrestricted double angle);
+
     Float32Array toFloat32Array();
     Float64Array toFloat64Array();
 };