GTTF: Make test launcher unset GTEST_ env variables since it handles all of sharding.

base/test/launcher/test_launcher.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/test/launcher/test_launcher.h"
 
 #if defined(OS_POSIX)
 #include <fcntl.h>
 #endif
 
@@ skipping 598 matching lines @@
   if (shard_index_ < 0 ||
       total_shards_ < 0 ||
       shard_index_ >= total_shards_) {
     LOG(ERROR) << "Invalid sharding settings: we require 0 <= "
                << kTestShardIndex << " < " << kTestTotalShards
                << ", but you have " << kTestShardIndex << "=" << shard_index_
                << ", " << kTestTotalShards << "=" << total_shards_ << ".\n";
     return false;
   }
 
+  // Make sure we don't pass any sharding-related environment to the child
+  // processes. This test launcher implements the sharding completely.
+  scoped_ptr<Environment> env(Environment::Create());
+  CHECK(env->UnSetVar("GTEST_TOTAL_SHARDS"));
+  CHECK(env->UnSetVar("GTEST_SHARD_INDEX"));
+
   if (command_line->HasSwitch(kGTestRepeatFlag) &&
       !StringToInt(command_line->GetSwitchValueASCII(kGTestRepeatFlag),
                    &cycles_)) {
     LOG(ERROR) << "Invalid value for " << kGTestRepeatFlag;
     return false;
   }
 
   // Split --gtest_filter at '-', if there is one, to separate into
   // positive filter and negative filter portions.
   std::string filter = command_line->GetSwitchValueASCII(kGTestFilterFlag);
@@ skipping 292 matching lines @@
 
     g_live_processes.Get().erase(process_handle);
   }
 
   base::CloseProcessHandle(process_handle);
 
   return exit_code;
 }
 
 }  // namespace base