Revert of Mojo EDK: Introduce MojoQueryHandleSignalsState API

mojo/public/c/system/functions.h

Index: mojo/public/c/system/functions.h
diff --git a/mojo/public/c/system/functions.h b/mojo/public/c/system/functions.h
index 4dad70b21d6ebfe6c32b3ed7f43914292d967e47..750a29ee0728c368c1ac8761f1129979ef0783b1 100644
--- a/mojo/public/c/system/functions.h
+++ b/mojo/public/c/system/functions.h
@@ -45,21 +45,6 @@
 // they properly overlap (this is likely the case with |MojoWait()|, etc.), or
 // fail with |MOJO_RESULT_INVALID_ARGUMENT| if they happen after.
 MOJO_SYSTEM_EXPORT MojoResult MojoClose(MojoHandle handle);
-
-// Queries the last known signals state of a handle.
-//
-// Note that no guarantees can be made about the accuracy of the returned
-// signals state by the time this returns, as other threads in the system may
-// change the handle's state at any time. Use with appropriate discretion.
-//
-// Returns:
-//   |MOJO_RESULT_OK| on success. |*signals_state| is populated with the
-//       last known signals state of |handle|.
-//   |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle or
-//       |signals_state| is null.
-MOJO_SYSTEM_EXPORT MojoResult
-MojoQueryHandleSignalsState(MojoHandle handle,
-                            struct MojoHandleSignalsState* signals_state);
 
 // Waits on the given handle until one of the following happens:
 //   - A signal indicated by |signals| is satisfied.