Make VideoCapturerAndroid work on SDK level 16

talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java

Index: talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java
diff --git a/talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java b/talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java
index 33402f700ba014c6393c1ea708bd1e3a5616bc30..0d8968aba9e50c17070e9d629e978edc078cb295 100644
--- a/talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java
+++ b/talk/app/webrtc/java/android/org/webrtc/ThreadUtils.java
@@ -126,4 +126,18 @@ final class ThreadUtils {
     awaitUninterruptibly(barrier);
     return result.value;
   }
+
+  /**
+   * Post |runner| to |handler| and wait for the result.
+   */
+  public static void invokeUninterruptibly(final Handler handler, final Runnable runner) {
+    final CountDownLatch barrier = new CountDownLatch(1);
+    handler.post(new Runnable() {
+      @Override public void run() {
+          runner.run();
+        barrier.countDown();
+      }
+    });
+    awaitUninterruptibly(barrier);
+  }
 }