Measuring data use of different ModelTypes in Sync Service.

sync/engine/syncer_unittest.cc

Index: sync/engine/syncer_unittest.cc
diff --git a/sync/engine/syncer_unittest.cc b/sync/engine/syncer_unittest.cc
index dcd326e8c887888ddab0eb867fafb20be8a07bcb..6e3e09d4dc702de8a7fb0810f948daff49adce89 100644
--- a/sync/engine/syncer_unittest.cc
+++ b/sync/engine/syncer_unittest.cc
@@ -20,6 +20,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "sync/engine/backoff_delay_provider.h"
@@ -666,6 +667,86 @@ TEST_F(SyncerTest, GetCommitIdsFiltersThrottledEntries) {
   }
 }
 
+// This test has three steps. In the first steps BOOKMARKS are sync and they are

[Nicolas Zea, 2015/08/18 21:55:18]

nit: "BOOKMARKS are sync and they are downloaded" -> "a BOOKMARKS update is
received".
Similarly, for the third step, "a BOOKMARK update is committed".

[amohammadkhan, 2015/08/19 17:33:35]

Done.

+// downloaded. In the next step, syncing BOOKMARKS is disabled, so no BOOKMARK
+// is uploaded or downloaded. In the last step, BOOKMARKS are uploaded and
+// committed to server.
+TEST_F(SyncerTest, DataUseHistogramsTest) {
+  base::HistogramTester histogram_tester;
+  const ModelTypeSet throttled_types(BOOKMARKS);

[Nicolas Zea, 2015/08/18 21:55:18]

throttled_types appears to be unused?

[amohammadkhan, 2015/08/19 17:33:36]

Done.

+  sync_pb::EntitySpecifics bookmark_data;
+  AddDefaultFieldValue(BOOKMARKS, &bookmark_data);
+
+  mock_server_->AddUpdateDirectory(1, 0, "A", 10, 10,
+                                   foreign_cache_guid(), "-1");
+  EXPECT_TRUE(SyncShareNudge());
+  {
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Count", 0);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Bytes", 0);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Count", 1);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Count",
+                                        BOOKMARKS, 1);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Bytes", 63);

[Nicolas Zea, 2015/08/18 21:55:18]

Where are these byte values from? It would be good if they could be calculated
on the fly. I worry that anyone who updates the proto message we commit/download
will also have to update these hardcoded byte values.

[amohammadkhan, 2015/08/19 17:33:35]

I got those values by test and you are right, they might be changed later. So I
changed the test function to not be dependent on these specific values anymore.

+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Bytes",
+                                        BOOKMARKS, 63);
+    histogram_tester.ExpectBucketCount("DataUse.Sync.ProgressMarker.Bytes",
+                                       BOOKMARKS, 28);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.ProgressMarker.Bytes", 84);
+
+    WriteTransaction wtrans(FROM_HERE, UNITTEST, directory());
+    MutableEntry A(&wtrans, GET_BY_ID, ids_.FromNumber(1));
+    A.PutIsUnsynced(true);
+    A.PutSpecifics(bookmark_data);
+    A.PutNonUniqueName("bookmark");
+  }
+
+  // Now sync without enabling bookmarks.
+  mock_server_->ExpectGetUpdatesRequestTypes(
+      Difference(context_->GetEnabledTypes(), ModelTypeSet(BOOKMARKS)));
+  ResetSession();
+  syncer_->NormalSyncShare(
+      Difference(context_->GetEnabledTypes(), ModelTypeSet(BOOKMARKS)),
+      &nudge_tracker_, session_.get());
+
+  {
+    // Nothing should have been committed as bookmarks is throttled.
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Count", 0);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Bytes", 0);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Count", 1);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Count",
+                                        BOOKMARKS, 1);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Bytes", 63);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Bytes",
+                                        BOOKMARKS, 63);
+    histogram_tester.ExpectBucketCount("DataUse.Sync.ProgressMarker.Bytes",
+                                       BOOKMARKS, 28);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.ProgressMarker.Bytes", 140);
+
+  }
+
+  // Sync again with bookmarks enabled.
+  mock_server_->ExpectGetUpdatesRequestTypes(context_->GetEnabledTypes());
+  EXPECT_TRUE(SyncShareNudge());
+  {
+    // It should have been committed.
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Count", 1);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Upload.Count",
+                                        BOOKMARKS, 1);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Upload.Bytes", 91);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Upload.Bytes",
+                                        BOOKMARKS, 91);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Count", 1);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Count",
+                                        BOOKMARKS, 1);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.Download.Bytes", 63);
+    histogram_tester.ExpectUniqueSample("DataUse.Sync.Download.Bytes",
+                                        BOOKMARKS, 63);
+    histogram_tester.ExpectBucketCount("DataUse.Sync.ProgressMarker.Bytes",
+                                       BOOKMARKS, 56);
+    histogram_tester.ExpectTotalCount("DataUse.Sync.ProgressMarker.Bytes", 224);
+  }
+}
+
 // We use a macro so we can preserve the error location.
 #define VERIFY_ENTRY(id, is_unapplied, is_unsynced, prev_initialized, \
                      parent_id, version, server_version, id_fac, rtrans) \