Revert making HandleWatcher block until no longer waiting on pipe (r285266).

mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java

Index: mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
diff --git a/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java b/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
index c9cd084d4cb4b789fb30db3d4395224499c49dc2..9b85895bfd2f3f5c77f8f4c051d7345b465b2e97 100644
--- a/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
+++ b/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
@@ -690,8 +690,8 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
-        Cancellable cancellable = core.getDefaultAsyncWaiter().asyncWait(handles.first,
-                Core.HandleSignals.READABLE, Core.DEADLINE_INFINITE, asyncWaiterResult);
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.HandleSignals.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
@@ -699,7 +699,7 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
-        cancellable.cancel();
+        handles.first.close();
         runLoopUntilIdle();
         // TODO(qsr) Re-enable when MojoWaitMany handles it correctly.
         // assertNull(asyncWaiterResult.getException());
@@ -710,6 +710,56 @@ public class CoreImplTest extends MojoTestCase {
      * Testing core {@link AsyncWaiter} implementation.
      */
     @SmallTest
+    public void testAsyncWaiterWaitingOnInvalidHandle() {
+        Core core = CoreImpl.getInstance();
+
+        // Closing the peer handle.
+        Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe(null);
+        addHandlePairToClose(handles);
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        handles.first.close();
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.HandleSignals.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        runLoopUntilIdle();
+        assertNotNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.INVALID_ARGUMENT,
+                asyncWaiterResult.getException().getMojoResult());
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+    }
+
+    /**
+     * Testing core {@link AsyncWaiter} implementation.
+     */
+    @SmallTest
+    public void testAsyncWaiterWaitingOnDefaultInvalidHandle() {
+        Core core = CoreImpl.getInstance();
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        core.getDefaultAsyncWaiter().asyncWait(InvalidHandle.INSTANCE, Core.HandleSignals.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        runLoopUntilIdle();
+        assertNotNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.INVALID_ARGUMENT, asyncWaiterResult.getException().getMojoResult());
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+    }
+
+    /**
+     * Testing core {@link AsyncWaiter} implementation.
+     */
+    @SmallTest
     public void testAsyncWaiterWaitingWithTimeout() {
         Core core = CoreImpl.getInstance();