PPAPI: Purposely leak ProxyLock, fix shutdown race

ppapi/proxy/ppapi_proxy_test.cc

Index: ppapi/proxy/ppapi_proxy_test.cc
diff --git a/ppapi/proxy/ppapi_proxy_test.cc b/ppapi/proxy/ppapi_proxy_test.cc
index 5e4b67bc4f3150ade7607547c6ba03294760b4fa..87aa22b2860a7f9e330a8ee4602cc43a15ebdf60 100644
--- a/ppapi/proxy/ppapi_proxy_test.cc
+++ b/ppapi/proxy/ppapi_proxy_test.cc
@@ -227,8 +227,12 @@ void PluginProxyTestHarness::CreatePluginGlobals() {
   if (globals_config_ == PER_THREAD_GLOBALS) {
     plugin_globals_.reset(new PluginGlobals(PpapiGlobals::PerThreadForTest()));
     PpapiGlobals::SetPpapiGlobalsOnThreadForTest(GetGlobals());
+    // Enable locking in case some other unit test ran before us and disabled
+    // locking.
+    ProxyLock::EnableLockingOnThreadForTest();
   } else {
     plugin_globals_.reset(new PluginGlobals());
+    ProxyLock::EnableLockingOnThreadForTest();
   }
 }
 
@@ -471,7 +475,10 @@ void HostProxyTestHarness::CreateHostGlobals() {
   if (globals_config_ == PER_THREAD_GLOBALS) {
     host_globals_.reset(new TestGlobals(PpapiGlobals::PerThreadForTest()));
     PpapiGlobals::SetPpapiGlobalsOnThreadForTest(GetGlobals());
+    // The host side of the proxy does not lock.
+    ProxyLock::DisableLockingOnThreadForTest();
   } else {
+    ProxyLock::DisableLockingOnThreadForTest();
     host_globals_.reset(new TestGlobals());
   }
 }