Adding a router class to handle messages that expect responses.

This also introduce the notion of message header to allow routing.

R=rmcilroy@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283767

Review URL: https://codereview.chromium.org/371603003

git-svn-id: http://src.chromium.org/svn/trunk/src/build@284170 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/lint/suppressions.xml

@@ -24,6 +24,10 @@ Still reading?
   <issue id="AllowBackup">
     <ignore path="AndroidManifest.xml"/>
   </issue>
+  <issue id="Assert">
+    <ignore regexp="mojo/public/java/src/.*"/>
+    <ignore regexp="mojo/bindings/java/src/.*"/>
+  </issue>
   <issue id="CommitPrefEdits">
     <ignore path="third_party/cacheinvalidation/src/java/com/google/ipc/invalidation/ticl/android2/channel/AndroidChannelPreferences.java"/>
   </issue>