Add pass operation on handles.

Also refactor tests to ease closing handles.

R=viettrungluu@chromium.org,rmcilroy@chromium.org

Review URL: https://codereview.chromium.org/325953006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@280215 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 522 insertions, 403 deletions

diff --git a/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java b/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
index 82b0f45..0144dbb 100644
--- a/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
+++ b/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
@@ -66,6 +66,14 @@ public class HandleMock implements UntypedHandle, MessagePipeHandle,
     }
 
     /**
+     * @see org.chromium.mojo.system.UntypedHandle#pass()
+     */
+    @Override
+    public HandleMock pass() {
+        return this;
+    }
+
+    /**
      * @see ConsumerHandle#discardData(int, DataPipe.ReadFlags)
      */
     @Override
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 928c4ef..2a3da5b 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
@@ -41,6 +41,38 @@ public class CoreImplTest extends MojoTestCase {
     private static final ScheduledExecutorService WORKER =
             Executors.newSingleThreadScheduledExecutor();
 
+    private List<Handle> mHandlesToClose = new ArrayList<Handle>();
+
+    /**
+     * @see MojoTestCase#tearDown()
+     */
+    @Override
+    protected void tearDown() throws Exception {
+        MojoException toThrow = null;
+        for (Handle handle : mHandlesToClose) {
+            try {
+                handle.close();
+            } catch (MojoException e) {
+                if (toThrow == null) {
+                    toThrow = e;
+                }
+            }
+        }
+        if (toThrow != null) {
+            throw toThrow;
+        }
+        super.tearDown();
+    }
+
+    private void addHandleToClose(Handle handle) {
+        mHandlesToClose.add(handle);
+    }
+
+    private void addHandlePairToClose(Pair<? extends Handle, ? extends Handle> handles) {
+        mHandlesToClose.add(handles.first);
+        mHandlesToClose.add(handles.second);
+    }
+
     /**
      * Runnable that will close the given handle.
      */
@@ -89,6 +121,53 @@ public class CoreImplTest extends MojoTestCase {
 
     }
 
+    private static void checkSendingData(DataPipe.ProducerHandle in, DataPipe.ConsumerHandle out) {
+        Random random = new Random();
+
+        // Writing a random 8 bytes message.
+        byte[] bytes = new byte[8];
+        random.nextBytes(bytes);
+        ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
+        buffer.put(bytes);
+        int result = in.writeData(buffer, DataPipe.WriteFlags.NONE);
+        assertEquals(bytes.length, result);
+
+        // Query number of bytes available.
+        result = out.readData(null, DataPipe.ReadFlags.none().query(true));
+        assertEquals(bytes.length, result);
+
+        // Read into a buffer.
+        ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length);
+        result = out.readData(receiveBuffer, DataPipe.ReadFlags.NONE);
+        assertEquals(bytes.length, result);
+        assertEquals(0, receiveBuffer.position());
+        assertEquals(bytes.length, receiveBuffer.limit());
+        byte[] receivedBytes = new byte[bytes.length];
+        receiveBuffer.get(receivedBytes);
+        assertTrue(Arrays.equals(bytes, receivedBytes));
+    }
+
+    private static void checkSharing(SharedBufferHandle in, SharedBufferHandle out) {
+        Random random = new Random();
+
+        ByteBuffer buffer1 = in.map(0, 8, SharedBufferHandle.MapFlags.NONE);
+        assertEquals(8, buffer1.capacity());
+        ByteBuffer buffer2 = out.map(0, 8, SharedBufferHandle.MapFlags.NONE);
+        assertEquals(8, buffer2.capacity());
+
+        byte[] bytes = new byte[8];
+        random.nextBytes(bytes);
+        buffer1.put(bytes);
+
+        byte[] receivedBytes = new byte[bytes.length];
+        buffer2.get(receivedBytes);
+
+        assertTrue(Arrays.equals(bytes, receivedBytes));
+
+        in.unmap(buffer1);
+        out.unmap(buffer2);
+    }
+
     /**
      * Testing {@link Core#waitMany(List, long)}.
      */
@@ -96,31 +175,26 @@ public class CoreImplTest extends MojoTestCase {
     public void testWaitMany() {
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-
-        try {
-            List<Pair<Handle, Core.WaitFlags>> handlesToWaitOn = new ArrayList<
-                    Pair<Handle, Core.WaitFlags>>();
-
-            handlesToWaitOn.add(
-                    new Pair<Handle, Core.WaitFlags>(handles.second, Core.WaitFlags.READABLE));
-            handlesToWaitOn.add(
-                    new Pair<Handle, Core.WaitFlags>(handles.first, Core.WaitFlags.WRITABLE));
-            WaitManyResult result = core.waitMany(handlesToWaitOn, 0);
-            assertEquals(MojoResult.OK, result.getMojoResult());
-            assertEquals(1, result.getHandleIndex());
-
-            handlesToWaitOn.clear();
-            handlesToWaitOn.add(
-                    new Pair<Handle, Core.WaitFlags>(handles.first, Core.WaitFlags.WRITABLE));
-            handlesToWaitOn.add(
-                    new Pair<Handle, Core.WaitFlags>(handles.second, Core.WaitFlags.READABLE));
-            result = core.waitMany(handlesToWaitOn, 0);
-            assertEquals(MojoResult.OK, result.getMojoResult());
-            assertEquals(0, result.getHandleIndex());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        List<Pair<Handle, Core.WaitFlags>> handlesToWaitOn = new ArrayList<
+                Pair<Handle, Core.WaitFlags>>();
+        handlesToWaitOn.add(
+                new Pair<Handle, Core.WaitFlags>(handles.second, Core.WaitFlags.READABLE));
+        handlesToWaitOn.add(
+                new Pair<Handle, Core.WaitFlags>(handles.first, Core.WaitFlags.WRITABLE));
+        WaitManyResult result = core.waitMany(handlesToWaitOn, 0);
+        assertEquals(MojoResult.OK, result.getMojoResult());
+        assertEquals(1, result.getHandleIndex());
+
+        handlesToWaitOn.clear();
+        handlesToWaitOn.add(
+                new Pair<Handle, Core.WaitFlags>(handles.first, Core.WaitFlags.WRITABLE));
+        handlesToWaitOn.add(
+                new Pair<Handle, Core.WaitFlags>(handles.second, Core.WaitFlags.READABLE));
+        result = core.waitMany(handlesToWaitOn, 0);
+        assertEquals(MojoResult.OK, result.getMojoResult());
+        assertEquals(0, result.getHandleIndex());
     }
 
     /**
@@ -131,32 +205,21 @@ public class CoreImplTest extends MojoTestCase {
         Core core = CoreImpl.getInstance();
 
         Pair<? extends Handle, ? extends Handle> handles = core.createMessagePipe();
-        try {
-            assertEquals(core, handles.first.getCore());
-            assertEquals(core, handles.second.getCore());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+        assertEquals(core, handles.first.getCore());
+        assertEquals(core, handles.second.getCore());
 
         handles = core.createDataPipe(null);
-        try {
-            assertEquals(core, handles.first.getCore());
-            assertEquals(core, handles.second.getCore());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+        assertEquals(core, handles.first.getCore());
+        assertEquals(core, handles.second.getCore());
 
         SharedBufferHandle handle = core.createSharedBuffer(null, 100);
         SharedBufferHandle handle2 = handle.duplicate(null);
-        try {
-            assertEquals(core, handle.getCore());
-            assertEquals(core, handle2.getCore());
-        } finally {
-            handle.close();
-            handle2.close();
-        }
+        addHandleToClose(handle);
+        addHandleToClose(handle2);
+        assertEquals(core, handle.getCore());
+        assertEquals(core, handle2.getCore());
     }
 
     /**
@@ -166,46 +229,36 @@ public class CoreImplTest extends MojoTestCase {
     public void testMessagePipeEmpty() {
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-
-        try {
-            // Testing wait.
-            assertEquals(MojoResult.OK, handles.first.wait(Core.WaitFlags.all(), 0));
-            assertEquals(MojoResult.OK, handles.first.wait(Core.WaitFlags.WRITABLE, 0));
-            assertEquals(MojoResult.DEADLINE_EXCEEDED,
-                    handles.first.wait(Core.WaitFlags.READABLE, 0));
-
-            // Testing read on an empty pipe.
-            MessagePipeHandle.ReadMessageResult result = handles.first.readMessage(null, 0,
-                    MessagePipeHandle.ReadFlags.NONE);
-            assertEquals(MojoResult.SHOULD_WAIT, result.getMojoResult());
-
-            // Closing a pipe while waiting.
-            WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
-            assertEquals(MojoResult.CANCELLED,
-                    handles.first.wait(Core.WaitFlags.READABLE, 1000000L));
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+        // Testing wait.
+        assertEquals(MojoResult.OK, handles.first.wait(Core.WaitFlags.all(), 0));
+        assertEquals(MojoResult.OK, handles.first.wait(Core.WaitFlags.WRITABLE, 0));
+        assertEquals(MojoResult.DEADLINE_EXCEEDED,
+                handles.first.wait(Core.WaitFlags.READABLE, 0));
+
+        // Testing read on an empty pipe.
+        MessagePipeHandle.ReadMessageResult result = handles.first.readMessage(null, 0,
+                MessagePipeHandle.ReadFlags.NONE);
+        assertEquals(MojoResult.SHOULD_WAIT, result.getMojoResult());
+
+        // Closing a pipe while waiting.
+        WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
+        assertEquals(MojoResult.CANCELLED,
+                handles.first.wait(Core.WaitFlags.READABLE, 1000000L));
 
         handles = core.createMessagePipe();
-
-        try {
-            // Closing the other pipe while waiting.
-            WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
-            assertEquals(MojoResult.FAILED_PRECONDITION,
-                    handles.second.wait(Core.WaitFlags.READABLE, 1000000L));
-
-            // Waiting on a closed pipe.
-            assertEquals(MojoResult.FAILED_PRECONDITION,
-                    handles.second.wait(Core.WaitFlags.READABLE, 0));
-            assertEquals(MojoResult.FAILED_PRECONDITION,
-                    handles.second.wait(Core.WaitFlags.WRITABLE, 0));
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
-
+        addHandlePairToClose(handles);
+
+        // Closing the other pipe while waiting.
+        WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
+        assertEquals(MojoResult.FAILED_PRECONDITION,
+                handles.second.wait(Core.WaitFlags.READABLE, 1000000L));
+
+        // Waiting on a closed pipe.
+        assertEquals(MojoResult.FAILED_PRECONDITION,
+                handles.second.wait(Core.WaitFlags.READABLE, 0));
+        assertEquals(MojoResult.FAILED_PRECONDITION,
+                handles.second.wait(Core.WaitFlags.WRITABLE, 0));
     }
 
     /**
@@ -215,14 +268,10 @@ public class CoreImplTest extends MojoTestCase {
     public void testMessagePipeSend() {
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
+        addHandlePairToClose(handles);
 
-        try {
-            checkSendingMessage(handles.first, handles.second);
-            checkSendingMessage(handles.second, handles.first);
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        checkSendingMessage(handles.first, handles.second);
+        checkSendingMessage(handles.second, handles.first);
     }
 
     /**
@@ -233,25 +282,21 @@ public class CoreImplTest extends MojoTestCase {
         Random random = new Random();
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
+        addHandlePairToClose(handles);
 
-        try {
-            // Writing a random 8 bytes message.
-            byte[] bytes = new byte[8];
-            random.nextBytes(bytes);
-            ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
-            buffer.put(bytes);
-            handles.first.writeMessage(buffer, null, MessagePipeHandle.WriteFlags.NONE);
-
-            ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(1);
-            MessagePipeHandle.ReadMessageResult result = handles.second
-                    .readMessage(receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
-            assertEquals(MojoResult.RESOURCE_EXHAUSTED, result.getMojoResult());
-            assertEquals(bytes.length, result.getMessageSize());
-            assertEquals(0, result.getHandlesCount());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        // Writing a random 8 bytes message.
+        byte[] bytes = new byte[8];
+        random.nextBytes(bytes);
+        ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
+        buffer.put(bytes);
+        handles.first.writeMessage(buffer, null, MessagePipeHandle.WriteFlags.NONE);
+
+        ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(1);
+        MessagePipeHandle.ReadMessageResult result = handles.second
+                .readMessage(receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
+        assertEquals(MojoResult.RESOURCE_EXHAUSTED, result.getMojoResult());
+        assertEquals(bytes.length, result.getMessageSize());
+        assertEquals(0, result.getHandlesCount());
     }
 
     /**
@@ -262,30 +307,22 @@ public class CoreImplTest extends MojoTestCase {
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
         Pair<MessagePipeHandle, MessagePipeHandle> handlesToShare = core.createMessagePipe();
-
-        try {
-            handles.first.writeMessage(null,
-                    Collections.<Handle> singletonList(handlesToShare.second),
-                    MessagePipeHandle.WriteFlags.NONE);
-            assertFalse(handlesToShare.second.isValid());
-            MessagePipeHandle.ReadMessageResult readMessageResult =
-                    handles.second.readMessage(null, 1, MessagePipeHandle.ReadFlags.NONE);
-            assertEquals(1, readMessageResult.getHandlesCount());
-            MessagePipeHandle newHandle = readMessageResult.getHandles().get(0)
-                    .toMessagePipeHandle();
-            try {
-                assertTrue(newHandle.isValid());
-                checkSendingMessage(handlesToShare.first, newHandle);
-                checkSendingMessage(newHandle, handlesToShare.first);
-            } finally {
-                newHandle.close();
-            }
-        } finally {
-            handles.first.close();
-            handles.second.close();
-            handlesToShare.first.close();
-            handlesToShare.second.close();
-        }
+        addHandlePairToClose(handles);
+        addHandlePairToClose(handlesToShare);
+
+        handles.first.writeMessage(null,
+                Collections.<Handle> singletonList(handlesToShare.second),
+                MessagePipeHandle.WriteFlags.NONE);
+        assertFalse(handlesToShare.second.isValid());
+        MessagePipeHandle.ReadMessageResult readMessageResult =
+                handles.second.readMessage(null, 1, MessagePipeHandle.ReadFlags.NONE);
+        assertEquals(1, readMessageResult.getHandlesCount());
+        MessagePipeHandle newHandle = readMessageResult.getHandles().get(0)
+                .toMessagePipeHandle();
+        addHandleToClose(newHandle);
+        assertTrue(newHandle.isValid());
+        checkSendingMessage(handlesToShare.first, newHandle);
+        checkSendingMessage(newHandle, handlesToShare.first);
     }
 
     private static void createAndCloseDataPipe(DataPipe.CreateOptions options) {
@@ -321,35 +358,11 @@ public class CoreImplTest extends MojoTestCase {
     @SmallTest
     public void testDataPipeSend() {
         Core core = CoreImpl.getInstance();
-        Random random = new Random();
 
         Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles = core.createDataPipe(null);
-        try {
-            // Writing a random 8 bytes message.
-            byte[] bytes = new byte[8];
-            random.nextBytes(bytes);
-            ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
-            buffer.put(bytes);
-            int result = handles.first.writeData(buffer, DataPipe.WriteFlags.NONE);
-            assertEquals(bytes.length, result);
-
-            // Query number of bytes available.
-            result = handles.second.readData(null, DataPipe.ReadFlags.none().query(true));
-            assertEquals(bytes.length, result);
-
-            // Read into a buffer.
-            ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length);
-            result = handles.second.readData(receiveBuffer, DataPipe.ReadFlags.NONE);
-            assertEquals(bytes.length, result);
-            assertEquals(0, receiveBuffer.position());
-            assertEquals(bytes.length, receiveBuffer.limit());
-            byte[] receivedBytes = new byte[bytes.length];
-            receiveBuffer.get(receivedBytes);
-            assertTrue(Arrays.equals(bytes, receivedBytes));
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        checkSendingData(handles.first, handles.second);
     }
 
     /**
@@ -360,30 +373,26 @@ public class CoreImplTest extends MojoTestCase {
         Random random = new Random();
         Core core = CoreImpl.getInstance();
         Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles = core.createDataPipe(null);
+        addHandlePairToClose(handles);
 
-        try {
-            // Writing a random 8 bytes message.
-            byte[] bytes = new byte[8];
-            random.nextBytes(bytes);
-            ByteBuffer buffer = handles.first.beginWriteData(bytes.length,
-                    DataPipe.WriteFlags.NONE);
-            assertTrue(buffer.capacity() >= bytes.length);
-            buffer.put(bytes);
-            handles.first.endWriteData(bytes.length);
-
-            // Read into a buffer.
-            ByteBuffer receiveBuffer = handles.second.beginReadData(bytes.length,
-                    DataPipe.ReadFlags.NONE);
-            assertEquals(0, receiveBuffer.position());
-            assertEquals(bytes.length, receiveBuffer.limit());
-            byte[] receivedBytes = new byte[bytes.length];
-            receiveBuffer.get(receivedBytes);
-            assertTrue(Arrays.equals(bytes, receivedBytes));
-            handles.second.endReadData(bytes.length);
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        // Writing a random 8 bytes message.
+        byte[] bytes = new byte[8];
+        random.nextBytes(bytes);
+        ByteBuffer buffer = handles.first.beginWriteData(bytes.length,
+                DataPipe.WriteFlags.NONE);
+        assertTrue(buffer.capacity() >= bytes.length);
+        buffer.put(bytes);
+        handles.first.endWriteData(bytes.length);
+
+        // Read into a buffer.
+        ByteBuffer receiveBuffer = handles.second.beginReadData(bytes.length,
+                DataPipe.ReadFlags.NONE);
+        assertEquals(0, receiveBuffer.position());
+        assertEquals(bytes.length, receiveBuffer.limit());
+        byte[] receivedBytes = new byte[bytes.length];
+        receiveBuffer.get(receivedBytes);
+        assertTrue(Arrays.equals(bytes, receivedBytes));
+        handles.second.endReadData(bytes.length);
     }
 
     /**
@@ -394,35 +403,31 @@ public class CoreImplTest extends MojoTestCase {
         Random random = new Random();
         Core core = CoreImpl.getInstance();
         Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles = core.createDataPipe(null);
+        addHandlePairToClose(handles);
 
-        try {
-            // Writing a random 8 bytes message.
-            byte[] bytes = new byte[8];
-            random.nextBytes(bytes);
-            ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
-            buffer.put(bytes);
-            int result = handles.first.writeData(buffer, DataPipe.WriteFlags.NONE);
-            assertEquals(bytes.length, result);
-
-            // Discard bytes.
-            final int nbBytesToDiscard = 4;
-            assertEquals(nbBytesToDiscard,
-                    handles.second.discardData(nbBytesToDiscard, DataPipe.ReadFlags.NONE));
-
-            // Read into a buffer.
-            ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length - nbBytesToDiscard);
-            result = handles.second.readData(receiveBuffer, DataPipe.ReadFlags.NONE);
-            assertEquals(bytes.length - nbBytesToDiscard, result);
-            assertEquals(0, receiveBuffer.position());
-            assertEquals(bytes.length - nbBytesToDiscard, receiveBuffer.limit());
-            byte[] receivedBytes = new byte[bytes.length - nbBytesToDiscard];
-            receiveBuffer.get(receivedBytes);
-            assertTrue(Arrays.equals(Arrays.copyOfRange(bytes, nbBytesToDiscard, bytes.length),
-                    receivedBytes));
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        // Writing a random 8 bytes message.
+        byte[] bytes = new byte[8];
+        random.nextBytes(bytes);
+        ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
+        buffer.put(bytes);
+        int result = handles.first.writeData(buffer, DataPipe.WriteFlags.NONE);
+        assertEquals(bytes.length, result);
+
+        // Discard bytes.
+        final int nbBytesToDiscard = 4;
+        assertEquals(nbBytesToDiscard,
+                handles.second.discardData(nbBytesToDiscard, DataPipe.ReadFlags.NONE));
+
+        // Read into a buffer.
+        ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length - nbBytesToDiscard);
+        result = handles.second.readData(receiveBuffer, DataPipe.ReadFlags.NONE);
+        assertEquals(bytes.length - nbBytesToDiscard, result);
+        assertEquals(0, receiveBuffer.position());
+        assertEquals(bytes.length - nbBytesToDiscard, receiveBuffer.limit());
+        byte[] receivedBytes = new byte[bytes.length - nbBytesToDiscard];
+        receiveBuffer.get(receivedBytes);
+        assertTrue(Arrays.equals(Arrays.copyOfRange(bytes, nbBytesToDiscard, bytes.length),
+                receivedBytes));
     }
 
     /**
@@ -434,7 +439,7 @@ public class CoreImplTest extends MojoTestCase {
         // Test creation with empty options.
         core.createSharedBuffer(null, 8).close();
         // Test creation with default options.
-        core.createSharedBuffer(new SharedBufferHandle.CreateOptions(), 8);
+        core.createSharedBuffer(new SharedBufferHandle.CreateOptions(), 8).close();
     }
 
     /**
@@ -444,14 +449,12 @@ public class CoreImplTest extends MojoTestCase {
     public void testSharedBufferDuplication() {
         Core core = CoreImpl.getInstance();
         SharedBufferHandle handle = core.createSharedBuffer(null, 8);
-        try {
-            // Test duplication with empty options.
-            handle.duplicate(null).close();
-            // Test creation with default options.
-            handle.duplicate(new SharedBufferHandle.DuplicateOptions()).close();
-        } finally {
-            handle.close();
-        }
+        addHandleToClose(handle);
+
+        // Test duplication with empty options.
+        handle.duplicate(null).close();
+        // Test creation with default options.
+        handle.duplicate(new SharedBufferHandle.DuplicateOptions()).close();
     }
 
     /**
@@ -459,32 +462,14 @@ public class CoreImplTest extends MojoTestCase {
      */
     @SmallTest
     public void testSharedBufferSending() {
-        Random random = new Random();
         Core core = CoreImpl.getInstance();
         SharedBufferHandle handle = core.createSharedBuffer(null, 8);
+        addHandleToClose(handle);
         SharedBufferHandle newHandle = handle.duplicate(null);
+        addHandleToClose(newHandle);
 
-        try {
-            ByteBuffer buffer1 = handle.map(0, 8, SharedBufferHandle.MapFlags.NONE);
-            assertEquals(8, buffer1.capacity());
-            ByteBuffer buffer2 = newHandle.map(0, 8, SharedBufferHandle.MapFlags.NONE);
-            assertEquals(8, buffer2.capacity());
-
-            byte[] bytes = new byte[8];
-            random.nextBytes(bytes);
-            buffer1.put(bytes);
-
-            byte[] receivedBytes = new byte[bytes.length];
-            buffer2.get(receivedBytes);
-
-            assertTrue(Arrays.equals(bytes, receivedBytes));
-
-            handle.unmap(buffer1);
-            newHandle.unmap(buffer2);
-        } finally {
-            handle.close();
-            newHandle.close();
-        }
+        checkSharing(handle, newHandle);
+        checkSharing(newHandle, handle);
     }
 
     /**
@@ -523,6 +508,7 @@ public class CoreImplTest extends MojoTestCase {
         // - Receive a INVALID_ARGUMENT exception
         // - Receive an invalid handle on the other side.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
+        addHandlePairToClose(handles);
         try {
             handles.first.writeMessage(null, Collections.<Handle> singletonList(handle),
                     MessagePipeHandle.WriteFlags.NONE);
@@ -532,9 +518,6 @@ public class CoreImplTest extends MojoTestCase {
             assertFalse(readMessageResult.getHandles().get(0).isValid());
         } catch (MojoException e) {
             assertEquals(MojoResult.INVALID_ARGUMENT, e.getMojoResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
         }
     }
 
@@ -583,25 +566,21 @@ public class CoreImplTest extends MojoTestCase {
 
         // Checking a correct result.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        addHandlePairToClose(handles);
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
 
-            core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
-                    Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
 
-            handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
-                    MessagePipeHandle.WriteFlags.NONE);
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertNull(asyncWaiterResult.getException());
-            assertEquals(MojoResult.OK, asyncWaiterResult.getResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
+                MessagePipeHandle.WriteFlags.NONE);
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.OK, asyncWaiterResult.getResult());
     }
 
     /**
@@ -613,28 +592,25 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
-                    Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            handles.second.close();
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertNull(asyncWaiterResult.getException());
-            assertEquals(MojoResult.FAILED_PRECONDITION, asyncWaiterResult.getResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        handles.second.close();
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.FAILED_PRECONDITION, asyncWaiterResult.getResult());
     }
 
     /**
@@ -646,29 +622,26 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
-                    Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            handles.first.close();
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            // TODO(qsr) Re-enable when MojoWaitMany handles it correctly.
-            // assertNull(asyncWaiterResult.getException());
-            // assertEquals(MojoResult.CANCELLED, asyncWaiterResult.getResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        handles.first.close();
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        // TODO(qsr) Re-enable when MojoWaitMany handles it correctly.
+        // assertNull(asyncWaiterResult.getException());
+        // assertEquals(MojoResult.CANCELLED, asyncWaiterResult.getResult());
     }
 
     /**
@@ -680,26 +653,23 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            handles.first.close();
-            core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
-                    Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertNotNull(asyncWaiterResult.getException());
-            assertEquals(MojoResult.INVALID_ARGUMENT,
-                    asyncWaiterResult.getException().getMojoResult());
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        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.WaitFlags.READABLE,
+                Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertNotNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.INVALID_ARGUMENT,
+                asyncWaiterResult.getException().getMojoResult());
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
     }
 
     /**
@@ -733,23 +703,20 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
-                    RUN_LOOP_TIMEOUT_MS, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            nativeRunLoop(10 * RUN_LOOP_TIMEOUT_MS);
-            assertNull(asyncWaiterResult.getException());
-            assertEquals(MojoResult.DEADLINE_EXCEEDED, asyncWaiterResult.getResult());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.WaitFlags.READABLE,
+                RUN_LOOP_TIMEOUT_MS, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        nativeRunLoop(10 * RUN_LOOP_TIMEOUT_MS);
+        assertNull(asyncWaiterResult.getException());
+        assertEquals(MojoResult.DEADLINE_EXCEEDED, asyncWaiterResult.getResult());
     }
 
     /**
@@ -761,34 +728,31 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        addHandlePairToClose(handles);
 
-            Cancellable cancellable = core.getDefaultAsyncWaiter().asyncWait(handles.first,
-                    Core.WaitFlags.READABLE, Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
 
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        Cancellable cancellable = core.getDefaultAsyncWaiter().asyncWait(handles.first,
+                Core.WaitFlags.READABLE, Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
 
-            cancellable.cancel();
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
 
-            handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
-                    MessagePipeHandle.WriteFlags.NONE);
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        cancellable.cancel();
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
+                MessagePipeHandle.WriteFlags.NONE);
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
     }
 
     /**
@@ -800,25 +764,87 @@ public class CoreImplTest extends MojoTestCase {
 
         // Closing the peer handle.
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
-        try {
-            final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
-            handles.first.close();
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-
-            Cancellable cancellable = core.getDefaultAsyncWaiter().asyncWait(handles.first,
-                    Core.WaitFlags.READABLE, Core.DEADLINE_INFINITE, asyncWaiterResult);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-            cancellable.cancel();
-
-            nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
-            assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
-            assertEquals(null, asyncWaiterResult.getException());
-        } finally {
-            handles.first.close();
-            handles.second.close();
-        }
+        addHandlePairToClose(handles);
+
+        final AsyncWaiterResult asyncWaiterResult = new AsyncWaiterResult();
+        handles.first.close();
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+
+        Cancellable cancellable = core.getDefaultAsyncWaiter().asyncWait(handles.first,
+                Core.WaitFlags.READABLE, Core.DEADLINE_INFINITE, asyncWaiterResult);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+        cancellable.cancel();
+
+        nativeRunLoop(RUN_LOOP_TIMEOUT_MS);
+        assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
+        assertEquals(null, asyncWaiterResult.getException());
+    }
+
+    /**
+     * Testing the pass method on message pipes.
+     */
+    @SmallTest
+    public void testMessagePipeHandlePass() {
+        Core core = CoreImpl.getInstance();
+        Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe();
+        addHandlePairToClose(handles);
+
+        assertTrue(handles.first.isValid());
+        MessagePipeHandle handleClone = handles.first.pass();
+
+        addHandleToClose(handleClone);
+
+        assertFalse(handles.first.isValid());
+        assertTrue(handleClone.isValid());
+        checkSendingMessage(handleClone, handles.second);
+        checkSendingMessage(handles.second, handleClone);
+    }
+
+    /**
+     * Testing the pass method on data pipes.
+     */
+    @SmallTest
+    public void testDataPipeHandlePass() {
+        Core core = CoreImpl.getInstance();
+        Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles = core.createDataPipe(null);
+        addHandlePairToClose(handles);
+
+        DataPipe.ProducerHandle producerClone = handles.first.pass();
+        DataPipe.ConsumerHandle consumerClone = handles.second.pass();
+
+        addHandleToClose(producerClone);
+        addHandleToClose(consumerClone);
+
+        assertFalse(handles.first.isValid());
+        assertFalse(handles.second.isValid());
+        assertTrue(producerClone.isValid());
+        assertTrue(consumerClone.isValid());
+        checkSendingData(producerClone, consumerClone);
+    }
+
+    /**
+     * Testing the pass method on shared buffers.
+     */
+    @SmallTest
+    public void testSharedBufferPass() {
+        Core core = CoreImpl.getInstance();
+        SharedBufferHandle handle = core.createSharedBuffer(null, 8);
+        addHandleToClose(handle);
+        SharedBufferHandle newHandle = handle.duplicate(null);
+        addHandleToClose(newHandle);
+
+        SharedBufferHandle handleClone = handle.pass();
+        SharedBufferHandle newHandleClone = newHandle.pass();
+
+        addHandleToClose(handleClone);
+        addHandleToClose(newHandleClone);
+
+        assertFalse(handle.isValid());
+        assertTrue(handleClone.isValid());
+        checkSharing(handleClone, newHandleClone);
+        checkSharing(newHandleClone, handleClone);
     }
 
 }
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeConsumerHandleImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeConsumerHandleImpl.java
index fa6a5c1..ab6f1ea 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeConsumerHandleImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeConsumerHandleImpl.java
@@ -24,11 +24,19 @@ class DataPipeConsumerHandleImpl extends HandleBase implements ConsumerHandle {
     /**
      * @see HandleBase#HandleBase(HandleBase)
      */
-    DataPipeConsumerHandleImpl(UntypedHandleImpl other) {
+    DataPipeConsumerHandleImpl(HandleBase other) {
         super(other);
     }
 
     /**
+     * @see org.chromium.mojo.system.Handle#pass()
+     */
+    @Override
+    public ConsumerHandle pass() {
+        return new DataPipeConsumerHandleImpl(this);
+    }
+
+    /**
      * @see ConsumerHandle#discardData(int, ReadFlags)
      */
     @Override
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeProducerHandleImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeProducerHandleImpl.java
index 308c8cc..1087a59 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeProducerHandleImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/DataPipeProducerHandleImpl.java
@@ -24,11 +24,19 @@ class DataPipeProducerHandleImpl extends HandleBase implements ProducerHandle {
     /**
      * @see HandleBase#HandleBase(HandleBase)
      */
-    DataPipeProducerHandleImpl(UntypedHandleImpl handle) {
+    DataPipeProducerHandleImpl(HandleBase handle) {
         super(handle);
     }
 
     /**
+     * @see org.chromium.mojo.system.DataPipe.ProducerHandle#pass()
+     */
+    @Override
+    public ProducerHandle pass() {
+        return new DataPipeProducerHandleImpl(this);
+    }
+
+    /**
      * @see ProducerHandle#writeData(ByteBuffer, WriteFlags)
      */
     @Override
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/MessagePipeHandleImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/MessagePipeHandleImpl.java
index 04d2776..345a558 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/MessagePipeHandleImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/MessagePipeHandleImpl.java
@@ -25,11 +25,19 @@ class MessagePipeHandleImpl extends HandleBase implements MessagePipeHandle {
     /**
      * @see HandleBase#HandleBase(HandleBase)
      */
-    MessagePipeHandleImpl(UntypedHandleImpl handle) {
+    MessagePipeHandleImpl(HandleBase handle) {
         super(handle);
     }
 
     /**
+     * @see org.chromium.mojo.system.MessagePipeHandle#pass()
+     */
+    @Override
+    public MessagePipeHandle pass() {
+        return new MessagePipeHandleImpl(this);
+    }
+
+    /**
      * @see MessagePipeHandle#writeMessage(ByteBuffer, List, WriteFlags)
      */
     @Override
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/SharedBufferHandleImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/SharedBufferHandleImpl.java
index c8cae1a..76ef739 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/SharedBufferHandleImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/SharedBufferHandleImpl.java
@@ -23,11 +23,19 @@ class SharedBufferHandleImpl extends HandleBase implements SharedBufferHandle {
     /**
      * @see HandleBase#HandleBase(HandleBase)
      */
-    SharedBufferHandleImpl(UntypedHandleImpl handle) {
+    SharedBufferHandleImpl(HandleBase handle) {
         super(handle);
     }
 
     /**
+     * @see org.chromium.mojo.system.SharedBufferHandle#pass()
+     */
+    @Override
+    public SharedBufferHandle pass() {
+        return new SharedBufferHandleImpl(this);
+    }
+
+    /**
      * @see SharedBufferHandle#duplicate(DuplicateOptions)
      */
     @Override
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/UntypedHandleImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/UntypedHandleImpl.java
index cfe72ba..4774ab8 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/UntypedHandleImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/UntypedHandleImpl.java
@@ -30,6 +30,14 @@ class UntypedHandleImpl extends HandleBase implements UntypedHandle {
     }
 
     /**
+     * @see org.chromium.mojo.system.UntypedHandle#pass()
+     */
+    @Override
+    public UntypedHandle pass() {
+        return new UntypedHandleImpl(this);
+    }
+
+    /**
      * @see org.chromium.mojo.system.UntypedHandle#toMessagePipeHandle()
      */
     @Override
diff --git a/mojo/public/java/src/org/chromium/mojo/system/DataPipe.java b/mojo/public/java/src/org/chromium/mojo/system/DataPipe.java
index 729612a..4cd74e1 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/DataPipe.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/DataPipe.java
@@ -213,6 +213,12 @@ public interface DataPipe {
     public static interface ProducerHandle extends Handle {
 
         /**
+         * @see org.chromium.mojo.system.Handle#pass()
+         */
+        @Override
+        public ProducerHandle pass();
+
+        /**
          * Writes the given data to the data pipe producer. |elements| points to data; the buffer
          * must be a direct ByteBuffer and the limit should be a multiple of the data pipe's element
          * size. If |allOrNone| is set in |flags|, either all the data will be written or none is.
@@ -272,6 +278,12 @@ public interface DataPipe {
     public static interface ConsumerHandle extends Handle {
 
         /**
+         * @see org.chromium.mojo.system.Handle#pass()
+         */
+        @Override
+        public ConsumerHandle pass();
+
+       /**
          * Discards data on the data pie consumer. This method discards up to |numBytes| (which
          * again be a multiple of the element size) bytes of data, returning the amount actually
          * discarded. if |flags| has |allOrNone|, it will either discard exactly |numBytes| bytes of
diff --git a/mojo/public/java/src/org/chromium/mojo/system/Handle.java b/mojo/public/java/src/org/chromium/mojo/system/Handle.java
index e738fb6..b4fcbd0 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/Handle.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/Handle.java
@@ -44,4 +44,10 @@ public interface Handle extends Closeable {
      */
     public Core getCore();
 
+    /**
+     * Passes ownership of the handle from this handle to the newly created Handle object,
+     * invalidating this handle object in the process.
+     */
+    public Handle pass();
+
 }
diff --git a/mojo/public/java/src/org/chromium/mojo/system/InvalidHandle.java b/mojo/public/java/src/org/chromium/mojo/system/InvalidHandle.java
index 2949aa7..e80132d 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/InvalidHandle.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/InvalidHandle.java
@@ -61,6 +61,15 @@ public class InvalidHandle implements UntypedHandle, MessagePipeHandle, Consumer
     }
 
     /**
+     * @see org.chromium.mojo.system.Handle#pass()
+     */
+    @Override
+    public InvalidHandle pass() {
+        return this;
+    }
+
+
+    /**
      * @see Handle#toUntypedHandle()
      */
     @Override
diff --git a/mojo/public/java/src/org/chromium/mojo/system/MessagePipeHandle.java b/mojo/public/java/src/org/chromium/mojo/system/MessagePipeHandle.java
index 086f626..cfb0327 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/MessagePipeHandle.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/MessagePipeHandle.java
@@ -83,18 +83,6 @@ public interface MessagePipeHandle extends Handle {
     }
 
     /**
-     * Writes a message to the message pipe endpoint, with message data specified by |bytes| and
-     * attached handles specified by |handles|, and options specified by |flags|. If there is no
-     * message data, |bytes| may be null, otherwise it must be a direct ByteBuffer. If there are no
-     * attached handles, |handles| may be null.
-     * <p>
-     * If handles are attached, on success the handles will no longer be valid (the receiver will
-     * receive equivalent, but logically different, handles). Handles to be sent should not be in
-     * simultaneous use (e.g., on another thread).
-     */
-    void writeMessage(ByteBuffer bytes, List<? extends Handle> handles, WriteFlags flags);
-
-    /**
      * Result of the |readMessage| method.
      */
     public static class ReadMessageResult {
@@ -175,6 +163,24 @@ public interface MessagePipeHandle extends Handle {
     }
 
     /**
+     * @see org.chromium.mojo.system.Handle#pass()
+     */
+    @Override
+    public MessagePipeHandle pass();
+
+    /**
+     * Writes a message to the message pipe endpoint, with message data specified by |bytes| and
+     * attached handles specified by |handles|, and options specified by |flags|. If there is no
+     * message data, |bytes| may be null, otherwise it must be a direct ByteBuffer. If there are no
+     * attached handles, |handles| may be null.
+     * <p>
+     * If handles are attached, on success the handles will no longer be valid (the receiver will
+     * receive equivalent, but logically different, handles). Handles to be sent should not be in
+     * simultaneous use (e.g., on another thread).
+     */
+    void writeMessage(ByteBuffer bytes, List<? extends Handle> handles, WriteFlags flags);
+
+    /**
      * Reads a message from the message pipe endpoint; also usable to query the size of the next
      * message or discard the next message. |bytes| indicate the buffer/buffer size to receive the
      * message data (if any) and |maxNumberOfHandles| indicate the maximum handle count to receive
diff --git a/mojo/public/java/src/org/chromium/mojo/system/SharedBufferHandle.java b/mojo/public/java/src/org/chromium/mojo/system/SharedBufferHandle.java
index d0a4bb7..b2eef0b 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/SharedBufferHandle.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/SharedBufferHandle.java
@@ -130,6 +130,12 @@ public interface SharedBufferHandle extends Handle {
     }
 
     /**
+     * @see org.chromium.mojo.system.Handle#pass()
+     */
+    @Override
+    public SharedBufferHandle pass();
+
+    /**
      * Duplicates the handle. This creates another handle (returned on success), which can then be
      * sent to another application over a message pipe, while retaining access to this handle (and
      * any mappings that it may have).
diff --git a/mojo/public/java/src/org/chromium/mojo/system/UntypedHandle.java b/mojo/public/java/src/org/chromium/mojo/system/UntypedHandle.java
index 4e9990f..199b0a1 100644
--- a/mojo/public/java/src/org/chromium/mojo/system/UntypedHandle.java
+++ b/mojo/public/java/src/org/chromium/mojo/system/UntypedHandle.java
@@ -15,6 +15,12 @@ import org.chromium.mojo.system.DataPipe.ProducerHandle;
 public interface UntypedHandle extends Handle {
 
     /**
+     * @see org.chromium.mojo.system.Handle#pass()
+     */
+    @Override
+    public UntypedHandle pass();
+
+    /**
      * Returns the underlying handle, as a {@link MessagePipeHandle}, invalidating this
      * representation.
      */