down-integrate internal changes
diff --git a/src/google/protobuf/any.cc b/src/google/protobuf/any.cc
new file mode 100644
index 0000000..c66fdfa
--- /dev/null
+++ b/src/google/protobuf/any.cc
@@ -0,0 +1,100 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// 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
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/any.h>
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+namespace {
+string GetTypeUrl(const Descriptor* message) {
+  return string(kTypeGoogleApisComPrefix) + message->full_name();
+}
+
+}  // namespace
+
+const char kAnyFullTypeName[] = "google.protobuf.Any";
+const char kTypeGoogleApisComPrefix[] = "type.googleapis.com/";
+
+AnyMetadata::AnyMetadata(UrlType* type_url, ValueType* value)
+    : type_url_(type_url), value_(value) {
+}
+
+void AnyMetadata::PackFrom(const Message& message) {
+  type_url_->SetNoArena(&::google::protobuf::internal::GetEmptyString(),
+      GetTypeUrl(message.GetDescriptor()));
+  message.SerializeToString(value_->MutableNoArena(
+      &::google::protobuf::internal::GetEmptyStringAlreadyInited()));
+}
+
+bool AnyMetadata::UnpackTo(Message* message) const {
+  if (!InternalIs(message->GetDescriptor())) {
+    return false;
+  }
+  return message->ParseFromString(
+      value_->GetNoArena(&::google::protobuf::internal::GetEmptyString()));
+}
+
+bool AnyMetadata::InternalIs(const Descriptor* descriptor) const {
+  return type_url_->GetNoArena(
+             &::google::protobuf::internal::GetEmptyString()) ==
+         GetTypeUrl(descriptor);
+}
+
+bool ParseAnyTypeUrl(const string& type_url, string* full_type_name) {
+  const int prefix_len = strlen(kTypeGoogleApisComPrefix);
+  if (strncmp(type_url.c_str(), kTypeGoogleApisComPrefix, prefix_len) == 0) {
+    full_type_name->assign(type_url.data() + prefix_len,
+                           type_url.size() - prefix_len);
+    return true;
+  }
+  return true;
+}
+
+
+bool GetAnyFieldDescriptors(const Message& message,
+                            const FieldDescriptor** type_url_field,
+                            const FieldDescriptor** value_field) {
+    const Descriptor* descriptor = message.GetDescriptor();
+    if (descriptor->full_name() != kAnyFullTypeName) {
+      return false;
+    }
+    *type_url_field = descriptor->FindFieldByNumber(1);
+    *value_field = descriptor->FindFieldByNumber(2);
+    return (*type_url_field != NULL &&
+            (*type_url_field)->type() == FieldDescriptor::TYPE_STRING &&
+            *value_field != NULL &&
+            (*value_field)->type() == FieldDescriptor::TYPE_BYTES);
+}
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google