Revert "Let InputReader handle its own thread"

This reverts commit ba266f24e580de2d8339050b62fad7e66441f843.

Reason for revert: b/143735040 looks like this CL breaks input tests

Change-Id: I8c19046935d2bdaf9df5df97b2eff43308065c72
diff --git a/services/inputflinger/InputManager.h b/services/inputflinger/InputManager.h
index 2a7ed0f..40f66d8 100644
--- a/services/inputflinger/InputManager.h
+++ b/services/inputflinger/InputManager.h
@@ -43,15 +43,15 @@
 /*
  * The input manager is the core of the system event processing.
  *
- * The input manager has two components.
+ * The input manager uses two threads.
  *
- * 1. The InputReader class starts a thread that reads and preprocesses raw input events, applies
- *    policy, and posts messages to a queue managed by the InputDispatcherThread.
+ * 1. The InputReaderThread (called "InputReader") reads and preprocesses raw input events,
+ *    applies policy, and posts messages to a queue managed by the DispatcherThread.
  * 2. The InputDispatcherThread (called "InputDispatcher") thread waits for new events on the
  *    queue and asynchronously dispatches them to applications.
  *
- * By design, the InputReader class and InputDispatcherThread class do not share any
- * internal state.  Moreover, all communication is done one way from the InputReader
+ * By design, the InputReaderThread class and InputDispatcherThread class do not share any
+ * internal state.  Moreover, all communication is done one way from the InputReaderThread
  * into the InputDispatcherThread and never the reverse.  Both classes may interact with the
  * InputDispatchPolicy, however.
  *
@@ -102,6 +102,7 @@
 
 private:
     sp<InputReaderInterface> mReader;
+    sp<InputReaderThread> mReaderThread;
 
     sp<InputClassifierInterface> mClassifier;