Support parallel captures from the StackSamplingProfiler.

base/threading/thread_restrictions.h

 // Copyright (c) 2012 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.
 
 #ifndef BASE_THREADING_THREAD_RESTRICTIONS_H_
 #define BASE_THREADING_THREAD_RESTRICTIONS_H_
 
 #include "base/base_export.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 74 matching lines @@
 namespace android {
 class JavaHandlerThread;
 }
 
 namespace internal {
 class TaskTracker;
 }
 
 class SequencedWorkerPool;
 class SimpleThread;
+class StackSamplingProfiler;
 class Thread;
 class ThreadTestHelper;
 
 // Certain behavior is disallowed on certain threads.  ThreadRestrictions helps
 // enforce these rules.  Examples of such rules:
 //
 // * Do not do blocking IO (makes the thread janky)
 // * Do not access Singleton/LazyInstance (may lead to shutdown crashes)
 //
 // Here's more about how the protection works:
@@ skipping 62 matching lines @@
   static void AssertIOAllowed() {}
   static bool SetSingletonAllowed(bool allowed) { return true; }
   static void AssertSingletonAllowed() {}
   static void DisallowWaiting() {}
   static void AssertWaitAllowed() {}
 #endif
 
  private:
   // DO NOT ADD ANY OTHER FRIEND STATEMENTS, talk to jam or brettw first.
   // BEGIN ALLOWED USAGE.
+  friend class base::StackSamplingProfiler;
   friend class content::BrowserShutdownProfileDumper;
   friend class content::BrowserSurfaceViewManager;
   friend class content::BrowserTestBase;
   friend class content::NestedMessagePumpAndroid;
   friend class content::ScopedAllowWaitForAndroidLayoutTests;
   friend class content::ScopedAllowWaitForDebugURL;
   friend class ::HistogramSynchronizer;
   friend class internal::TaskTracker;
   friend class ::ScopedAllowWaitForLegacyWebViewApi;
   friend class cc::CompletionEvent;
@@ skipping 59 matching lines @@
 
     DISALLOW_COPY_AND_ASSIGN(ScopedAllowWait);
   };
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(ThreadRestrictions);
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_THREAD_RESTRICTIONS_H_