Return created channels synchronously

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index 9efefb729ecf0598a7523fca2f6dab2b2bfd7f8b..f1625b489bd16acdb69ed5656ef93343bf35add0 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -84,7 +84,8 @@ import java.util.concurrent.Callable;
  * continuous build & test in the open source SDK-based tree).
  */
 @JNINamespace("android_webview")
-public class AwContents implements SmartClipProvider {
+public class AwContents implements SmartClipProvider,
+        PostMessageSender.PostMessageSenderDelegate {
     private static final String TAG = "AwContents";
 
     private static final String WEB_ARCHIVE_EXTENSION = ".mht";
@@ -246,6 +247,8 @@ public class AwContents implements SmartClipProvider {
     private AwViewMethods mAwViewMethods;
     private final FullScreenTransitionsState mFullScreenTransitionsState;
 
+    private PostMessageSender mPostMessageSender;
+
     // This flag indicates that ShouldOverrideUrlNavigation should be posted
     // through the resourcethrottle. This is only used for popup windows.
     private boolean mDeferredShouldOverrideUrlLoadingIsPendingForPopup;
@@ -910,6 +913,12 @@ public class AwContents implements SmartClipProvider {
      */
     public void destroy() {
         if (isDestroyed()) return;
+
+        if  (mPostMessageSender != null) {
+            mBrowserContext.getMessagePortService().removeObserver(mPostMessageSender);
+            mPostMessageSender = null;
+        }
+
         // If we are attached, we have to call native detach to clean up
         // hardware resources.
         if (mIsAttachedToWindow) {
@@ -1790,29 +1799,31 @@ public class AwContents implements SmartClipProvider {
     public void postMessageToFrame(String frameName, String message,
             String sourceOrigin, String targetOrigin, MessagePort[] sentPorts) {
         if (isDestroyed()) return;
-        int[] portIds = null;
-        if (sentPorts != null) {
-            portIds = new int[sentPorts.length];
-            for (int i = 0; i < sentPorts.length; i++) {
-                portIds[i] = sentPorts[i].portId();
-            }
-            mBrowserContext.getMessagePortService().removeSentPorts(portIds);
+        if (mPostMessageSender == null) {

[hush (inactive), 2015/02/13 03:25:08]

Just to make it clear here:

mPostMessageSender is only responsible for sending messages to frames. Sending
messages from port 1 to port 2 are done by the ports themselves, because the
ports have their own postMessageSenders (even though AwContents might have
created a message channel that consists of port 1 and port 2)

[sgurun-gerrit only, 2015/02/13 05:11:59]

yes, exactly. Messages can be posted either from a webview directly to a frame,
(or main frame) or using a message port of a message channel.

+            AwMessagePortService service = mBrowserContext.getMessagePortService();
+            mPostMessageSender = new PostMessageSender(this, service);
+            service.addObserver(mPostMessageSender);
         }
+        mPostMessageSender.postMessage(frameName, message, sourceOrigin, targetOrigin,
+                sentPorts);
+    }
+
+    @Override
+    public void postMessageToWeb(String frameName, String message,
+            String sourceOrigin, String targetOrigin, int[] sentPorts) {

[hush (inactive), 2015/02/13 03:25:08]

so the subtle difference between postMessageToFrame is we're sending the port
ids instead of messageport objects in this method.
Could you rename "sentPorts" to "sentPortIds"?

This method basically "postMessageForReal", right?

Anyways, please add a description for this method.

[sgurun-gerrit only, 2015/02/13 05:11:59]

done
yes.
done (at the public interface)/

+        if (isDestroyed()) return;
         nativePostMessageToFrame(mNativeAwContents, frameName, message, sourceOrigin,
-                targetOrigin, portIds);
+                targetOrigin, sentPorts);
     }
 
     /**
-     * Creates a message channel and asynchronously returns the ports that
-     * forms the ports for each end of the channel.
-     *
-     * @param callback The message channel created.
+     * Creates a message channel and returns the ports for each end of the channel.
      */
-    public void createMessageChannel(ValueCallback<MessagePort[]> callback) {
-        if (isDestroyed()) return;
-        // Make sure the message port service is created.
-        mBrowserContext.createMessagePortServiceIfNecessary();
-        nativeCreateMessageChannel(mNativeAwContents, callback);
+    public MessagePort[] createMessageChannel() {
+        if (isDestroyed()) return null;
+        MessagePort[] ports = mBrowserContext.getMessagePortService().createMessageChannel();
+        nativeCreateMessageChannel(mNativeAwContents, ports);
+        return ports;
     }
 
     //--------------------------------------------------------------------------------------------
@@ -2708,6 +2719,5 @@ public class AwContents implements SmartClipProvider {
     private native void nativePostMessageToFrame(long nativeAwContents, String frameId,
             String message, String sourceOrigin, String targetOrigin, int[] msgPorts);
 
-    private native void nativeCreateMessageChannel(long nativeAwContents,
-            ValueCallback<MessagePort[]> callback);
+    private native void nativeCreateMessageChannel(long nativeAwContents, MessagePort[] ports);
 }