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

base/test/launcher/test_launcher.cc

Index: base/test/launcher/test_launcher.cc
diff --git a/base/test/launcher/test_launcher.cc b/base/test/launcher/test_launcher.cc
index f7f967958c5f6028a36496a109c8eaffa2748802..a9bebf2ccea03ed5f3bb2c6788598a485a2d4a74 100644
--- a/base/test/launcher/test_launcher.cc
+++ b/base/test/launcher/test_launcher.cc
@@ -616,6 +616,12 @@ bool TestLauncher::Init() {
     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_)) {