Implement inverse & invertSelf function in DOMMatrix & DOMMatrixReadOnly.

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

Index: third_party/WebKit/Source/core/dom/DOMMatrix.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMMatrix.cpp b/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
index 14a1d8e9641ce9a097c1a470bc8aea5bfbaccdcb..db646afbe8987770b3bd76662db55ddaaf987cfc 100644
--- a/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
@@ -118,4 +118,30 @@ DOMMatrix* DOMMatrix::skewYSelf(double sy)
     return this;
 }
 
+DOMMatrix* DOMMatrix::invertSelf()
+{
+    if (m_matrix->isInvertible()) {
+        m_matrix = TransformationMatrix::create(m_matrix->inverse());
+    } else {
+        setM11(std::nan(""));

[dominicc (has gone to gerrit), 2016/08/30 02:22:09]

Hmm, I haven't done any numerical programming with C++, but this is a bit of a
surprise. There's no constant or macro for this?

[Hwanseung Lee, 2016/08/30 12:47:05]

Done.

+        setM12(std::nan(""));
+        setM13(std::nan(""));
+        setM14(std::nan(""));
+        setM21(std::nan(""));
+        setM22(std::nan(""));
+        setM23(std::nan(""));
+        setM24(std::nan(""));
+        setM31(std::nan(""));
+        setM32(std::nan(""));
+        setM33(std::nan(""));
+        setM34(std::nan(""));
+        setM41(std::nan(""));
+        setM42(std::nan(""));
+        setM43(std::nan(""));
+        setM44(std::nan(""));
+        setIs2D(false);
+    }
+    return this;
+}
+
 } // namespace blink