Initialize the message center as part of the testing browser process

chrome/browser/browser_process_impl.h

Index: chrome/browser/browser_process_impl.h
diff --git a/chrome/browser/browser_process_impl.h b/chrome/browser/browser_process_impl.h
index eb2a9cae4a8ccdfce2b956618a3d79d24df116e6..2f37cbee4c8ac3f83fcbcee04476c7ca612c5bf6 100644
--- a/chrome/browser/browser_process_impl.h
+++ b/chrome/browser/browser_process_impl.h
@@ -160,6 +160,11 @@ class BrowserProcessImpl : public BrowserProcess,
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
+  friend class BrowserProcessImplTest;
+
+  BrowserProcessImpl(base::SequencedTaskRunner* local_state_task_runner,
+                     const base::CommandLine& command_line,
+                     bool initialize_message_center);
   // KeepAliveStateObserver implementation
   void OnKeepAliveStateChanged(bool is_keeping_alive) override;
   void OnKeepAliveRestartStateChanged(bool can_restart) override;
@@ -350,6 +355,10 @@ class BrowserProcessImpl : public BrowserProcess,
 
   std::unique_ptr<PhysicalWebDataSource> physical_web_data_source_;
 
+  // Whether to skip initialization of the global message center
+  // used in some tests.
+  bool initialize_message_center_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserProcessImpl);
 };