AU: Try delta updates first, then full updates

Also, some bug fixes.

Review URL: http://codereview.chromium.org/492008
diff --git a/integration_unittest.cc b/integration_unittest.cc
index e8eca56..13102da 100644
--- a/integration_unittest.cc
+++ b/integration_unittest.cc
@@ -40,7 +40,7 @@
   virtual ~IntegrationTestProcessorDelegate() {
     EXPECT_TRUE(processing_done_called_);
   }
-  virtual void ProcessingDone(const ActionProcessor* processor) {
+  virtual void ProcessingDone(const ActionProcessor* processor, bool success) {
     processing_done_called_ = true;
     g_main_loop_quit(loop_);
   }