Removed some unsafe uses of StringShape....

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 694)
+++ src/objects.cc	(working copy)
@@ -3717,21 +3717,6 @@
 }
 
 
-Object* SlicedString::SlicedStringFlatten() {
-  // The SlicedString constructor should ensure that there are no
-  // SlicedStrings that are constructed directly on top of other
-  // SlicedStrings.
-  String* buf = String::cast(buffer());
-  StringShape buf_shape(buf);
-  ASSERT(!buf_shape.IsSliced());
-  if (buf_shape.IsCons()) {
-    Object* ok = buf->Flatten(buf_shape);
-    if (ok->IsFailure()) return ok;
-  }
-  return this;
-}
-
-
 template <typename sinkchar>
 void String::WriteToFlat(String* src,
                          StringShape src_shape,
@@ -3975,8 +3960,7 @@
 
 
 bool String::MarkAsUndetectable() {
-  StringShape shape(this);
-  if (shape.IsSymbol()) return false;
+  if (StringShape(this).IsSymbol()) return false;
 
   Map* map = this->map();
   if (map == Heap::short_string_map()) {
@@ -4134,7 +4118,8 @@
 }
 
 
-Object* String::Slice(StringShape shape, int start, int end) {
+Object* String::Slice(int start, int end) {
+  StringShape shape(this);
   if (start == 0 && end == length(shape)) return this;
   if (shape.representation_tag() == kSlicedStringTag) {
     // Translate slices of a SlicedString into slices of the
@@ -4142,11 +4127,10 @@
     SlicedString* str = SlicedString::cast(this);
     String* buf = str->buffer();
     return Heap::AllocateSlicedString(buf,
-                                      StringShape(buf),
                                       str->start() + start,
                                       str->start() + end);
   }
-  Object* result = Heap::AllocateSlicedString(this, shape, start, end);
+  Object* result = Heap::AllocateSlicedString(this, start, end);
   if (result->IsFailure()) {
     return result;
   }