[Cronet] Fix race in UploadDataStream.attachToRequest.

components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java

Index: components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java
diff --git a/components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java b/components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java
index e03e97dde1463e8ce594a9b54d2bc6355fd0c5de..d0a72fa350b5993fcced5d1a59e6509dd2a5e92d 100644
--- a/components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java
+++ b/components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.java
@@ -211,10 +211,15 @@ final class CronetUrlRequest implements UrlRequest {
                                 "Requests with upload data must have a Content-Type.");
                     }
                     mStarted = true;
-                    mUploadDataStream.attachToRequest(this, mUrlRequestAdapter, new Runnable() {
+                    mUploadDataStream.postTaskToExecutor(new Runnable() {
                         @Override
                         public void run() {
+                            mUploadDataStream.initializeWithRequest(CronetUrlRequest.this);
                             synchronized (mUrlRequestAdapterLock) {
+                                if (isDoneLocked()) {
+                                    return;
+                                }
+                                mUploadDataStream.attachNativeAdapterToRequest(mUrlRequestAdapter);
                                 startInternalLocked();
                             }
                         }
@@ -234,6 +239,7 @@ final class CronetUrlRequest implements UrlRequest {
 
     @GuardedBy("mUrlRequestAdapterLock")
     private void startInternalLocked() {
+        // Caller is expected to ensure that request isn't done and mUrlRequestAdapter is valid.

[xunjieli, 2016/03/10 22:40:54]

nit: maybe make this comment to the method level (java doc) where it is more
visible.

[mef, 2016/03/11 15:43:06]

Done. I wonder whether we should just put isDoneLocked check here for good
measure.

[xunjieli, 2016/03/11 15:44:32]

I am not sure. Your call :)

         if (mDisableCache) {
             nativeDisableCache(mUrlRequestAdapter);
         }