base: Move renderer threads to the appropriate cpuset.

base/threading/platform_thread.h

Index: base/threading/platform_thread.h
diff --git a/base/threading/platform_thread.h b/base/threading/platform_thread.h
index 4c2db8aba78a1f817288bce6b11c1f29b2397b5c..70217946da01970d2c454ab337539a049f3bd3d8 100644
--- a/base/threading/platform_thread.h
+++ b/base/threading/platform_thread.h
@@ -205,6 +205,13 @@ class BASE_EXPORT PlatformThread {
 
   static ThreadPriority GetCurrentThreadPriority();
 
+#if defined(OS_LINUX)
+  // Warning: Don't use this for a main thread because that will change the
+  // whole thread group's (i.e. process) priority.
+  static void SetThreadPriority(PlatformThreadId thread_id,
+                                ThreadPriority priority);
+#endif

[Avi (use Gerrit), 2016/09/16 22:26:29]

You ifdef this to the platform, but don't ifdef any of the other code. Why?

[reveman, 2016/09/16 23:06:41]

What other code are you referring to? I didn't ifdef the IPC messages to linux
but can do that if preferred? The rest of the code should already be limited to
linux either through ifdefs or by being in a file that's only built on linux.

[Avi (use Gerrit), 2016/09/17 00:55:54]

Yes, I'm referring to the RenderMessageFilter code, etc.

[reveman, 2016/09/17 09:13:36]

Latest patch will ifdef all the code to linux only. Makes sense until we use it
elsewhere.

+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformThread);
 };