Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h

Index: third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h
diff --git a/third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h b/third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h
index 4360b18f5e918425f7d4851f752354ea54781781..153f543ee4b0cb25656f86c09b3a5bc4349aba9a 100644
--- a/third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h
+++ b/third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
+// http://code.google.com/p/protobuf/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -48,7 +48,6 @@
 #include <iosfwd>
 #include <google/protobuf/io/zero_copy_stream.h>
 #include <google/protobuf/stubs/common.h>
-#include <google/protobuf/stubs/stl_util.h>
 
 
 namespace google {
@@ -127,10 +126,8 @@ class LIBPROTOBUF_EXPORT ArrayOutputStream : public ZeroCopyOutputStream {
 class LIBPROTOBUF_EXPORT StringOutputStream : public ZeroCopyOutputStream {
  public:
   // Create a StringOutputStream which appends bytes to the given string.
-  // The string remains property of the caller, but it is mutated in arbitrary
-  // ways and MUST NOT be accessed in any way until you're done with the
-  // stream. Either be sure there's no further usage, or (safest) destroy the
-  // stream before using the contents.
+  // The string remains property of the caller, but it MUST NOT be accessed
+  // in any way until the stream is destroyed.
   //
   // Hint:  If you call target->reserve(n) before creating the stream,
   //   the first call to Next() will return at least n bytes of buffer
@@ -336,44 +333,6 @@ class LIBPROTOBUF_EXPORT CopyingOutputStreamAdaptor : public ZeroCopyOutputStrea
 
 // ===================================================================
 
-// mutable_string_data() and as_string_data() are workarounds to improve
-// the performance of writing new data to an existing string.  Unfortunately
-// the methods provided by the string class are suboptimal, and using memcpy()
-// is mildly annoying because it requires its pointer args to be non-NULL even
-// if we ask it to copy 0 bytes.  Furthermore, string_as_array() has the
-// property that it always returns NULL if its arg is the empty string, exactly
-// what we want to avoid if we're using it in conjunction with memcpy()!
-// With C++11, the desired memcpy() boils down to memcpy(..., &(*s)[0], size),
-// where s is a string*.  Without C++11, &(*s)[0] is not guaranteed to be safe,
-// so we use string_as_array(), and live with the extra logic that tests whether
-// *s is empty.
-
-// Return a pointer to mutable characters underlying the given string.  The
-// return value is valid until the next time the string is resized.  We
-// trust the caller to treat the return value as an array of length s->size().
-inline char* mutable_string_data(string* s) {
-#ifdef LANG_CXX11
-  // This should be simpler & faster than string_as_array() because the latter
-  // is guaranteed to return NULL when *s is empty, so it has to check for that.
-  return &(*s)[0];
-#else
-  return string_as_array(s);
-#endif
-}
-
-// as_string_data(s) is equivalent to
-//  ({ char* p = mutable_string_data(s); make_pair(p, p != NULL); })
-// Sometimes it's faster: in some scenarios p cannot be NULL, and then the
-// code can avoid that check.
-inline std::pair<char*, bool> as_string_data(string* s) {
-  char *p = mutable_string_data(s);
-#ifdef LANG_CXX11
-  return std::make_pair(p, true);
-#else
-  return make_pair(p, p != NULL);
-#endif
-}
-
 }  // namespace io
 }  // namespace protobuf