Make it possible to have 1 PpapiGlobals per thread. Update unit tests.

webkit/plugins/ppapi/host_globals.cc

Index: webkit/plugins/ppapi/host_globals.cc
diff --git a/webkit/plugins/ppapi/host_globals.cc b/webkit/plugins/ppapi/host_globals.cc
index ab5198353992e43f9a5fbed69a349db243caa016..826245c5404401a9bb12e8a56d81ee27cdfe8143 100644
--- a/webkit/plugins/ppapi/host_globals.cc
+++ b/webkit/plugins/ppapi/host_globals.cc
@@ -45,8 +45,13 @@ HostGlobals::HostGlobals() : ::ppapi::PpapiGlobals() {
   host_globals_ = this;
 }
 
+HostGlobals::HostGlobals(::ppapi::PpapiGlobals::ForTest for_test)
+    : ::ppapi::PpapiGlobals(for_test) {
+  DCHECK(!host_globals_);
+}
+
 HostGlobals::~HostGlobals() {
-  DCHECK(host_globals_ == this);
+  DCHECK(host_globals_ == this || !host_globals_);
   host_globals_ = NULL;
 }
 
@@ -116,6 +121,11 @@ PP_Module HostGlobals::GetModuleForInstance(PP_Instance instance) {
   return inst->module()->pp_module();
 }
 
+base::Lock* HostGlobals::GetProxyLock() {
+  // We do not lock on the host side.
+  return NULL;
+}
+
 PP_Module HostGlobals::AddModule(PluginModule* module) {
 #ifndef NDEBUG
   // Make sure we're not adding one more than once.