Update //third_party/protobuf to version 3.

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 153f543ee4b0cb25656f86c09b3a5bc4349aba9a..a598ef2e3d196cd37c718fc87f5b543beb7ab7b2 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.
-// http://code.google.com/p/protobuf/
+// https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -44,10 +44,16 @@
 #ifndef GOOGLE_PROTOBUF_IO_ZERO_COPY_STREAM_IMPL_LITE_H__
 #define GOOGLE_PROTOBUF_IO_ZERO_COPY_STREAM_IMPL_LITE_H__
 
+#include <memory>
+#ifndef _SHARED_PTR_H
+#include <google/protobuf/stubs/shared_ptr.h>
+#endif
 #include <string>
 #include <iosfwd>
 #include <google/protobuf/io/zero_copy_stream.h>
 #include <google/protobuf/stubs/common.h>
+#include <google/protobuf/stubs/scoped_ptr.h>
+#include <google/protobuf/stubs/stl_util.h>
 
 
 namespace google {
@@ -126,8 +132,10 @@ 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 MUST NOT be accessed
-  // in any way until the stream is destroyed.
+  // 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.
   //
   // Hint:  If you call target->reserve(n) before creating the stream,
   //   the first call to Next() will return at least n bytes of buffer
@@ -231,7 +239,7 @@ class LIBPROTOBUF_EXPORT CopyingInputStreamAdaptor : public ZeroCopyInputStream
 
   // Data is read into this buffer.  It may be NULL if no buffer is currently
   // in use.  Otherwise, it points to an array of size buffer_size_.
-  scoped_array<uint8> buffer_;
+  google::protobuf::scoped_array<uint8> buffer_;
   const int buffer_size_;
 
   // Number of valid bytes currently in the buffer (i.e. the size last
@@ -320,7 +328,7 @@ class LIBPROTOBUF_EXPORT CopyingOutputStreamAdaptor : public ZeroCopyOutputStrea
 
   // Data is written from this buffer.  It may be NULL if no buffer is
   // currently in use.  Otherwise, it points to an array of size buffer_size_.
-  scoped_array<uint8> buffer_;
+  google::protobuf::scoped_array<uint8> buffer_;
   const int buffer_size_;
 
   // Number of valid bytes currently in the buffer (i.e. the size last
@@ -333,6 +341,44 @@ 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