Add GetLiveVars to PPB_Testing_Dev. Fix leaks it uncovered.

ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc

Index: ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc
diff --git a/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc b/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc
index 636302cf21035750066f9bf1ddcb6ce74189be64..b1728695e6f4907ea8ddb4f0c89d8c63fac31bd7 100644
--- a/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc
+++ b/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.cc
@@ -16,6 +16,17 @@ namespace {
 
 pthread_mutex_t mu = PTHREAD_MUTEX_INITIALIZER;
 
+// Convert the given SharedProxyVar to a PP_Var, incrementing the reference
+// count by 1.
+PP_Var GetPPVar(const SharedProxyVar& proxy_var) {
+  PP_Var var;
+  var.type = proxy_var->pp_var_type();
+  var.padding = 0;
+  var.value.as_id = proxy_var->id();
+  proxy_var->AddRef();
+  return var;
+}
+
 }  // namespace
 
 ProxyVarCache* ProxyVarCache::cache_singleton = NULL;
@@ -86,4 +97,15 @@ SharedProxyVar ProxyVarCache::SharedProxyVarForVar(PP_Var pp_var) const {
   return proxy_var;
 }
 
+std::vector<PP_Var> ProxyVarCache::GetLiveVars() {
+  std::vector<PP_Var> live_vars;
+  pthread_mutex_lock(&mu);
+  for (ProxyVarDictionary::const_iterator iter(proxy_var_cache_.begin());
+       iter != proxy_var_cache_.end();
+       ++iter)
+    live_vars.push_back(GetPPVar(iter->second));
+  pthread_mutex_unlock(&mu);
+  return live_vars;
+}
+
 }  // namespace ppapi_proxy