Eliminate potential for flaky crash in BCKSFactory::SetTestingFactory().

components/browser_context_keyed_service/browser_context_dependency_manager.cc

 // Copyright (c) 2013 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 "components/browser_context_keyed_service/browser_context_dependency_manager.h"
 
 #include <algorithm>
 #include <deque>
 #include <iterator>
 
@@ skipping 53 matching lines @@
     content::BrowserContext* context) {
   DoCreateBrowserContextServices(context, true);
 }
 
 void BrowserContextDependencyManager::DoCreateBrowserContextServices(
     content::BrowserContext* context,
     bool is_testing_context) {
   TRACE_EVENT0("browser",
     "BrowserContextDependencyManager::DoCreateBrowserContextServices")
 #ifndef NDEBUG
-  // Unmark |context| as dead. This exists because of unit tests, which will
-  // often have similar stack structures. 0xWhatever might be created, go out
-  // of scope, and then a new BrowserContext object might be created
-  // at 0xWhatever.
-  dead_context_pointers_.erase(context);
+  MarkBrowserContextLiveForTesting(context);
 #endif
 
   std::vector<DependencyNode*> construction_order;
   if (!dependency_graph_.GetConstructionOrder(&construction_order)) {
     NOTREACHED();
   }
 
 #ifndef NDEBUG
   DumpBrowserContextDependencies(context);
 #endif
@@ skipping 43 matching lines @@
 void BrowserContextDependencyManager::AssertBrowserContextWasntDestroyed(
     content::BrowserContext* context) {
   if (dead_context_pointers_.find(context) != dead_context_pointers_.end()) {
     NOTREACHED() << "Attempted to access a BrowserContext that was ShutDown(). "
                  << "This is most likely a heap smasher in progress. After "
                  << "BrowserContextKeyedService::Shutdown() completes, your "
                  << "service MUST NOT refer to depended BrowserContext "
                  << "services again.";
   }
 }
+
+void BrowserContextDependencyManager::MarkBrowserContextLiveForTesting(
+    content::BrowserContext* context) {
+  dead_context_pointers_.erase(context);
+}
 #endif
 
 // static
 BrowserContextDependencyManager*
 BrowserContextDependencyManager::GetInstance() {
   return Singleton<BrowserContextDependencyManager>::get();
 }
 
 BrowserContextDependencyManager::BrowserContextDependencyManager() {
 }
@@ skipping 18 matching lines @@
           kDumpBrowserContextDependencyGraphFlag)) {
     base::FilePath dot_file =
         context->GetPath().AppendASCII("browser-context-dependencies.dot");
     std::string contents = dependency_graph_.DumpAsGraphviz(
         "BrowserContext",
         base::Bind(&BrowserContextKeyedBaseFactoryGetNodeName));
     file_util::WriteFile(dot_file, contents.c_str(), contents.size());
   }
 }
 #endif  // NDEBUG