Reland 9034035: Make it possible to have 1 PpapiGlobals per thread.

ppapi/shared_impl/ppapi_globals.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/shared_impl/ppapi_globals.h"
 
+#include "base/lazy_instance.h"  // For testing purposes only.
 #include "base/logging.h"
+#include "base/threading/thread_local.h"  // For testing purposes only.
 
 namespace ppapi {
 
+namespace {
+// Thread-local globals for testing. See SetPpapiGlobalsOnThreadForTest for more
+// information.
+base::LazyInstance<
+    base::ThreadLocalPointer<PpapiGlobals>,
+    base::LeakyLazyInstanceTraits<base::ThreadLocalPointer<PpapiGlobals> > >
+        tls_ppapi_globals_for_test = LAZY_INSTANCE_INITIALIZER;
+}  // namespace
+
 PpapiGlobals* PpapiGlobals::ppapi_globals_ = NULL;
 
 PpapiGlobals::PpapiGlobals() {
   DCHECK(!ppapi_globals_);
   ppapi_globals_ = this;
 }
 
+PpapiGlobals::PpapiGlobals(ForTest) {
+  DCHECK(!ppapi_globals_);
+}
+
 PpapiGlobals::~PpapiGlobals() {
-  DCHECK(ppapi_globals_ == this);
+  DCHECK(ppapi_globals_ == this || !ppapi_globals_);
   ppapi_globals_ = NULL;
 }
 
+// static
+void PpapiGlobals::SetPpapiGlobalsOnThreadForTest(PpapiGlobals* ptr) {
+  // If we're using a per-thread PpapiGlobals, we should not have a global one.
+  // If we allowed it, it would always over-ride the "test" versions.
+  DCHECK(!ppapi_globals_);
+  tls_ppapi_globals_for_test.Pointer()->Set(ptr);
+}
+
+bool PpapiGlobals::IsHostGlobals() const {
+  return false;
+}
+
+bool PpapiGlobals::IsPluginGlobals() const {
+  return false;
+}
+
+// static
+PpapiGlobals* PpapiGlobals::GetThreadLocalPointer() {
+  return tls_ppapi_globals_for_test.Pointer()->Get();
+}
+
 }  // namespace ppapi