third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/testing/googletest.cc

 // 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.
@@ skipping 48 matching lines @@
 #ifndef O_BINARY
 #ifdef _O_BINARY
 #define O_BINARY _O_BINARY
 #else
 #define O_BINARY 0     // If this isn't defined, the platform doesn't need it.
 #endif
 #endif
 
 string TestSourceDir() {
 #ifndef GOOGLE_THIRD_PARTY_PROTOBUF
+#ifdef GOOGLE_PROTOBUF_TEST_SOURCE_PATH
+  return GOOGLE_PROTOBUF_TEST_SOURCE_PATH;
+#else
 #ifndef _MSC_VER
   // automake sets the "srcdir" environment variable.
   char* result = getenv("srcdir");
   if (result != NULL) {
     return result;
   }
 #endif  // _MSC_VER
 
   // Look for the "src" directory.
   string prefix = ".";
 
   while (!File::Exists(prefix + "/src/google/protobuf")) {
     if (!File::Exists(prefix)) {
       GOOGLE_LOG(FATAL)
         << "Could not find protobuf source code.  Please run tests from "
            "somewhere within the protobuf source package.";
     }
     prefix += "/..";
   }
   return prefix + "/src";
+#endif  // GOOGLE_PROTOBUF_TEST_SOURCE_PATH
 #else
   return "third_party/protobuf/src";
 #endif  // GOOGLE_THIRD_PARTY_PROTOBUF
 }
 
 namespace {
 
 string GetTemporaryDirectoryName() {
   // Tests run under Bazel "should not" use /tmp. Bazel sets this environment
   // variable for tests to use instead.
@@ skipping 159 matching lines @@
 struct ForceShutdown {
   ~ForceShutdown() {
     ShutdownProtobufLibrary();
   }
 } force_shutdown;
 
 }  // namespace
 
 }  // namespace protobuf
 }  // namespace google