AU: Optimize checkpointing a bit and decide on new update vs. resume.

BUG=7390
TEST=unit tests, gmerged on device

Change-Id: Ibed6082fe697e6b28b03fb1cc39d700826bf2bfe

Review URL: http://codereview.chromium.org/3541016
diff --git a/download_action_unittest.cc b/download_action_unittest.cc
index 3e8aabd..7571fb4 100644
--- a/download_action_unittest.cc
+++ b/download_action_unittest.cc
@@ -102,6 +102,7 @@
       OmahaHashCalculator::OmahaHashOfData(data);
   uint64_t size = data.size() + (size_test ? 1 : 0);
   InstallPlan install_plan(true,
+                           false,
                            "",
                            size,
                            hash,
@@ -227,7 +228,7 @@
 
     // takes ownership of passed in HttpFetcher
     ObjectFeederAction<InstallPlan> feeder_action;
-    InstallPlan install_plan(true, "", 0, "", temp_file.GetPath(), "");
+    InstallPlan install_plan(true, false, "", 0, "", temp_file.GetPath(), "");
     feeder_action.set_obj(install_plan);
     PrefsMock prefs;
     DownloadAction download_action(&prefs,
@@ -326,6 +327,7 @@
 
   // takes ownership of passed in HttpFetcher
   InstallPlan install_plan(true,
+                           false,
                            "",
                            1,
                            OmahaHashCalculator::OmahaHashOfString("x"),
@@ -364,7 +366,7 @@
   DirectFileWriter writer;
 
   // takes ownership of passed in HttpFetcher
-  InstallPlan install_plan(true, "", 0, "", path, "");
+  InstallPlan install_plan(true, false, "", 0, "", path, "");
   ObjectFeederAction<InstallPlan> feeder_action;
   feeder_action.set_obj(install_plan);
   PrefsMock prefs;