Introduce new constructor to PlatformThread.

webrtc/base/platform_thread.h

Index: webrtc/base/platform_thread.h
diff --git a/webrtc/base/platform_thread.h b/webrtc/base/platform_thread.h
index 667407fabc4299b034ae7ad0203044ba6caecf89..ed26ca03cc70d1e2d05814b05733c02d34241de8 100644
--- a/webrtc/base/platform_thread.h
+++ b/webrtc/base/platform_thread.h
@@ -32,7 +32,8 @@ void SetCurrentThreadName(const char* name);
 // Callback function that the spawned thread will enter once spawned.
 // A return value of false is interpreted as that the function has no
 // more work to do and that the thread can be released.
-typedef bool (*ThreadRunFunction)(void*);
+typedef bool (*ThreadRunFunctionDeprecated)(void*);
+typedef void (*ThreadRunFunction)(void*);
 
 enum ThreadPriority {
 #ifdef WEBRTC_WIN
@@ -55,7 +56,13 @@ enum ThreadPriority {
 // called from the same thread, including instantiation.
 class PlatformThread {
  public:
-  PlatformThread(ThreadRunFunction func, void* obj, const char* thread_name);
+  PlatformThread(ThreadRunFunctionDeprecated func,
+                 void* obj,
+                 const char* thread_name);
+  PlatformThread(ThreadRunFunction func,
+                 void* obj,
+                 const char* thread_name,
+                 ThreadPriority priority = kNormalPriority);
   virtual ~PlatformThread();
 
   const std::string& name() const { return name_; }
@@ -74,6 +81,7 @@ class PlatformThread {
   void Stop();
 
   // Set the priority of the thread. Must be called when thread is running.
+  // TODO(tommi): Make private and only allow public support via ctor.
   bool SetPriority(ThreadPriority priority);
 
  protected:
@@ -85,12 +93,15 @@ class PlatformThread {
  private:
   void Run();
 
-  ThreadRunFunction const run_function_;
+  ThreadRunFunctionDeprecated const run_function_deprecated_ = nullptr;
+  ThreadRunFunction const run_function_ = nullptr;
+  const ThreadPriority priority_ = kNormalPriority;
   void* const obj_;
   // TODO(pbos): Make sure call sites use string literals and update to a const
   // char* instead of a std::string.
   const std::string name_;
   rtc::ThreadChecker thread_checker_;
+  rtc::ThreadChecker spawned_thread_checker_;
 #if defined(WEBRTC_WIN)
   static DWORD WINAPI StartThread(void* param);