Refactored fast external string resource getter.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 3b9bb0a13783fd6829bbffe3a678b6babeeb08c4..f2f37cfb482333e55a40d789487e90b95fb7c003 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -398,6 +398,13 @@ bool StringShape::IsExternalAscii() {
 }
 
 
+STATIC_CHECK((kExternalStringTag | kAsciiStringTag) ==
+             Internals::kExternalAsciiRepresentationTag);
+
+STATIC_CHECK(v8::String::kExternalAsciiStringType ==
+             Internals::kExternalAsciiRepresentationTag);
+
+
 bool StringShape::IsExternalTwoByte() {
   return full_representation_tag() == (kExternalStringTag | kTwoByteStringTag);
 }
@@ -406,6 +413,8 @@ bool StringShape::IsExternalTwoByte() {
 STATIC_CHECK((kExternalStringTag | kTwoByteStringTag) ==
              Internals::kExternalTwoByteRepresentationTag);
 
+STATIC_CHECK(v8::String::kExternalTwoByteStringType ==
+             Internals::kExternalTwoByteRepresentationTag);
 
 uc32 FlatStringReader::Get(int index) {
   ASSERT(0 <= index && index <= length_);