[css-typed-om] add toMatrix() method in CSSTransformValue.idl

third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp

Index: third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp b/third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp
index 8fa84ef432d644124b31e16b87e0d27662ff7456..4c9c44a90a8533cb60f83261292649f642a5e0bc 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp
+++ b/third_party/WebKit/Source/core/css/cssom/CSSTransformValue.cpp
@@ -5,7 +5,9 @@
 #include "core/css/cssom/CSSTransformValue.h"
 
 #include "core/css/CSSValueList.h"
+#include "core/css/cssom/CSSMatrixComponent.h"
 #include "core/css/cssom/CSSTransformComponent.h"
+#include "core/geometry/DOMMatrix.h"
 
 namespace blink {
 
@@ -34,6 +36,17 @@ bool CSSTransformValue::is2D() const {
   return true;
 }
 
+DOMMatrix* CSSTransformValue::toMatrix() const {
+  DOMMatrix* matrix = DOMMatrix::Create();
+  for (size_t i = 0; i < transform_components_.size(); i++) {
+    CSSMatrixComponent* matrixComponent = transform_components_[i]->asMatrix();
+    if (matrixComponent) {
+      matrix->multiplySelf(matrixComponent->matrix());
+    }
+  }
+  return matrix;
+}
+
 const CSSValue* CSSTransformValue::ToCSSValue() const {
   CSSValueList* transform_css_value = CSSValueList::CreateSpaceSeparated();
   for (size_t i = 0; i < transform_components_.size(); i++) {