GeometryInterface: Add DOMMatrixInit and fromMatrix().

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

Index: third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.idl
diff --git a/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.idl b/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.idl
index 356487c820ad2c9c7e101fccdc26f00865bf5997..440bba4e0d943f7c319c9d54d6a48e358ff3732e 100644
--- a/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.idl
+++ b/third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.idl
@@ -10,6 +10,8 @@
     // FIXME: Exposed=(Window,Worker)
     RuntimeEnabled=GeometryInterfaces,
 ] interface DOMMatrixReadOnly {
+    [RaisesException, NewObject] static DOMMatrixReadOnly fromMatrix(optional DOMMatrixInit other);
+
     // These attributes are simple aliases for certain elements of the 4x4 matrix
     readonly attribute unrestricted double a;
     readonly attribute unrestricted double b;
@@ -56,9 +58,9 @@
                               optional unrestricted double originX = 0,
                               optional unrestricted double originY = 0,
                               optional unrestricted double originZ = 0);
-    DOMMatrix multiply(DOMMatrix other);
     DOMMatrix skewX(optional unrestricted double sx = 0);
     DOMMatrix skewY(optional unrestricted double sy = 0);
+    [RaisesException] DOMMatrix multiply(optional DOMMatrixInit other);
     DOMMatrix flipX();
     DOMMatrix flipY();
     DOMMatrix inverse();