Oilpan: fix build after r183596.

TBR=haraken,oilpan-reviews
BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/648193002

git-svn-id: svn://svn.chromium.org/blink/trunk@183602 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

@@ -589,7 +589,7 @@ float StyleBuilderConverter::convertPerspective(StyleResolverState& state, CSSVa
 
     // CSSPropertyWebkitPerspective accepts unitless numbers.
     if (primitiveValue->isNumber()) {
-        RefPtr<CSSPrimitiveValue> px = CSSPrimitiveValue::create(primitiveValue->getDoubleValue(), CSSPrimitiveValue::CSS_PX);
+        RefPtrWillBeRawPtr<CSSPrimitiveValue> px = CSSPrimitiveValue::create(primitiveValue->getDoubleValue(), CSSPrimitiveValue::CSS_PX);
         return convertPerspectiveLength(state, px.get());
     }