diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/synchronizer/ConcurrentRecordConsumer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/synchronizer/ConcurrentRecordConsumer.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,122 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.sync.synchronizer;
+
+import org.mozilla.gecko.background.common.log.Logger;
+import org.mozilla.gecko.sync.repositories.domain.Record;
+
+/**
+ * Consume records from a queue inside a RecordsChannel, as fast as we can.
+ * TODO: rewrite this in terms of an ExecutorService and a CompletionService.
+ * See Bug 713483.
+ *
+ * @author rnewman
+ *
+ */
+class ConcurrentRecordConsumer extends RecordConsumer {
+  private static final String LOG_TAG = "CRecordConsumer";
+
+  /**
+   * When this is true and all records have been processed, the consumer
+   * will notify its delegate.
+   */
+  protected boolean allRecordsQueued = false;
+  private long counter = 0;
+
+  public ConcurrentRecordConsumer(RecordsConsumerDelegate delegate) {
+    this.delegate = delegate;
+  }
+
+  private Object monitor = new Object();
+  @Override
+  public void doNotify() {
+    synchronized (monitor) {
+      monitor.notify();
+    }
+  }
+
+  @Override
+  public void queueFilled() {
+    Logger.debug(LOG_TAG, "Queue filled.");
+    synchronized (monitor) {
+      this.allRecordsQueued = true;
+      monitor.notify();
+    }
+  }
+
+  @Override
+  public void halt() {
+    synchronized (monitor) {
+      this.stopImmediately = true;
+      monitor.notify();
+    }
+  }
+
+  private Object countMonitor = new Object();
+  @Override
+  public void stored() {
+    Logger.trace(LOG_TAG, "Record stored. Notifying.");
+    synchronized (countMonitor) {
+      counter++;
+    }
+  }
+
+  private void consumerIsDone() {
+    Logger.debug(LOG_TAG, "Consumer is done. Processed " + counter + ((counter == 1) ? " record." : " records."));
+    delegate.consumerIsDone(!allRecordsQueued);
+  }
+
+  @Override
+  public void run() {
+    Record record;
+
+    while (true) {
+      // The queue is concurrent-safe.
+      while ((record = delegate.getQueue().poll()) != null) {
+        synchronized (monitor) {
+          Logger.trace(LOG_TAG, "run() took monitor.");
+          if (stopImmediately) {
+            Logger.debug(LOG_TAG, "Stopping immediately. Clearing queue.");
+            delegate.getQueue().clear();
+            Logger.debug(LOG_TAG, "Notifying consumer.");
+            consumerIsDone();
+            return;
+          }
+          Logger.debug(LOG_TAG, "run() dropped monitor.");
+        }
+
+        Logger.trace(LOG_TAG, "Storing record with guid " + record.guid + ".");
+        try {
+          delegate.store(record);
+        } catch (Exception e) {
+          // TODO: Bug 709371: track records that failed to apply.
+          Logger.error(LOG_TAG, "Caught error in store.", e);
+        }
+        Logger.trace(LOG_TAG, "Done with record.");
+      }
+      synchronized (monitor) {
+        Logger.trace(LOG_TAG, "run() took monitor.");
+
+        if (allRecordsQueued) {
+          Logger.debug(LOG_TAG, "Done with records and no more to come. Notifying consumerIsDone.");
+          consumerIsDone();
+          return;
+        }
+        if (stopImmediately) {
+          Logger.debug(LOG_TAG, "Done with records and told to stop immediately. Notifying consumerIsDone.");
+          consumerIsDone();
+          return;
+        }
+        try {
+          Logger.debug(LOG_TAG, "Not told to stop but no records. Waiting.");
+          monitor.wait(10000);
+        } catch (InterruptedException e) {
+          // TODO
+        }
+        Logger.trace(LOG_TAG, "run() dropped monitor.");
+      }
+    }
+  }
+}