Support additive animations on CSS property transform

third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp

Index: third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp
diff --git a/third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp b/third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp
index a197e9ded6a457651d35a59c5a57eb2538c5b29f..c4113fd2b84fc8a7fa54cbc9386ffd53237923ed 100644
--- a/third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp
+++ b/third_party/WebKit/Source/core/animation/PropertyInterpolationTypesMapping.cpp
@@ -29,6 +29,7 @@
 #include "core/animation/CSSShadowListInterpolationType.h"
 #include "core/animation/CSSSizeListInterpolationType.h"
 #include "core/animation/CSSTextIndentInterpolationType.h"
+#include "core/animation/CSSTransformInterpolationType.h"
 #include "core/animation/CSSTransformOriginInterpolationType.h"
 #include "core/animation/CSSTranslateInterpolationType.h"
 #include "core/animation/CSSValueInterpolationType.h"
@@ -244,6 +245,9 @@ const InterpolationTypes* PropertyInterpolationTypesMapping::get(const PropertyH
         case CSSPropertyWebkitFilter:
             applicableTypes->append(adoptPtr(new CSSFilterListInterpolationType(cssProperty)));
             break;
+        case CSSPropertyTransform:
+            applicableTypes->append(adoptPtr(new CSSTransformInterpolationType(cssProperty)));
+            break;
         default:
             // TODO(alancutter): Support all interpolable CSS properties here so we can stop falling back to the old StyleInterpolation implementation.
             if (CSSPropertyMetadata::isInterpolableProperty(cssProperty))