Fix unit test to allow repeated successful runs by avoiding a function static variable in tests.

ppapi/shared_impl/test_globals.cc

Index: ppapi/shared_impl/test_globals.cc
diff --git a/ppapi/shared_impl/test_globals.cc b/ppapi/shared_impl/test_globals.cc
index f8997dcb8d4c8f6ef709fb46f219c7c278bc650c..d154a9883f23b2f7464104a70ea1fa609cc8aed8 100644
--- a/ppapi/shared_impl/test_globals.cc
+++ b/ppapi/shared_impl/test_globals.cc
@@ -4,6 +4,8 @@
 
 #include "ppapi/shared_impl/test_globals.h"
 
+#include "base/message_loop_proxy.h"
+
 namespace ppapi {
 
 TestGlobals::TestGlobals()
@@ -46,6 +48,12 @@ PP_Module TestGlobals::GetModuleForInstance(PP_Instance instance) {
   return 0;
 }
 
+base::MessageLoopProxy* TestGlobals::GetMainThreadMessageLoop() {
+  if (!message_loop_proxy_.get())
+    message_loop_proxy_ = base::MessageLoopProxy::current();
+  return message_loop_proxy_.get();
+}
+
 std::string TestGlobals::GetCmdLine() {
   return std::string();
 }