Turn isEmpty check in parseSimpleTransform into ASSERT

Source/core/css/parser/CSSParserFastPaths.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/css/parser/CSSParserFastPaths.h"
 
 #include "core/StylePropertyShorthand.h"
 #include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSValuePool.h"
@@ skipping 620 matching lines @@
         if (pos < end) {
             if (isCSSSpace(*pos))
                 return nullptr;
         }
     }
     return transformList.release();
 }
 
 static PassRefPtrWillBeRawPtr<CSSValue> parseSimpleTransform(CSSPropertyID propertyID, const String& string)
 {
+    ASSERT(!string.isEmpty());
+
     if (propertyID != CSSPropertyTransform)
         return nullptr;
-    if (string.isEmpty())
-        return nullptr;
     if (string.is8Bit()) {
         const LChar* pos = string.characters8();
         const LChar* end = pos + string.length();
         return parseSimpleTransformList(pos, end);
     }
     const UChar* pos = string.characters16();
     const UChar* end = pos + string.length();
     return parseSimpleTransformList(pos, end);
 }
 
 PassRefPtrWillBeRawPtr<CSSValue> CSSParserFastPaths::maybeParseValue(CSSPropertyID propertyID, const String& string, CSSParserMode parserMode)
 {
     if (RefPtrWillBeRawPtr<CSSValue> length = parseSimpleLengthValue(propertyID, string, parserMode))
         return length.release();
     if (RefPtrWillBeRawPtr<CSSValue> color = parseColorValue(propertyID, string, parserMode))
         return color.release();
     if (RefPtrWillBeRawPtr<CSSValue> keyword = parseKeywordValue(propertyID, string))
         return keyword.release();
     if (RefPtrWillBeRawPtr<CSSValue> transform = parseSimpleTransform(propertyID, string))
         return transform.release();
     return nullptr;
 }
 
 } // namespace blink