Add a BrowserThread::DCheckCurrentlyOn function.

content/browser/browser_thread_impl.cc

 // 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.
 
 #include "content/browser/browser_thread_impl.h"
 
 #include <string>
 
 #include "base/atomicops.h"
 #include "base/bind.h"
@@ skipping 347 matching lines @@
   // http://crbug.com/63678
   base::ThreadRestrictions::ScopedAllowSingleton allow_singleton;
   BrowserThreadGlobals& globals = g_globals.Get();
   base::AutoLock lock(globals.lock);
   DCHECK(identifier >= 0 && identifier < ID_COUNT);
   return globals.threads[identifier] &&
          globals.threads[identifier]->message_loop() ==
              base::MessageLoop::current();
 }
 
+static const char* GetThreadName(BrowserThread::ID thread) {
+  if (BrowserThread::UI < thread && thread < BrowserThread::ID_COUNT)
+    return g_browser_thread_names[thread];
+  if (thread == BrowserThread::UI)
+    return "Chrome_UIThread";
+  return "Unknown Thread";
+}
+
+// static
+std::string BrowserThread::GetDCheckCurrentlyOnErrorMessage(ID expected) {
+  const std::string& message_loop_name =
+      base::MessageLoop::current()->thread_name();
+  ID actual_browser_thread;
+  const char* actual_name = "Unknown Thread";
+  if (!message_loop_name.empty()) {
+    actual_name = message_loop_name.c_str();
+  } else if (GetCurrentThreadIdentifier(&actual_browser_thread)) {
+    actual_name = GetThreadName(actual_browser_thread);
+  }
+  std::string result = "Must be called on ";
+  result += GetThreadName(expected);
+  result += "; actually called on ";
+  result += actual_name;
+  result += ".";
+  return result;
+}
+
 // static
 bool BrowserThread::IsMessageLoopValid(ID identifier) {
   if (g_globals == NULL)
     return false;
 
   BrowserThreadGlobals& globals = g_globals.Get();
   base::AutoLock lock(globals.lock);
   DCHECK(identifier >= 0 && identifier < ID_COUNT);
   return globals.threads[identifier] &&
          globals.threads[identifier]->message_loop();
@@ skipping 96 matching lines @@
   AtomicWord* storage = reinterpret_cast<AtomicWord*>(
       &globals.thread_delegates[identifier]);
   AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange(
       storage, reinterpret_cast<AtomicWord>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_pointer);
 }
 
 }  // namespace content