sync: Fix backend configuration to support sync db refresh.

Removes the has_new bit in favor of checking if initial_sync_ended for requested types, and recreates the sync db on corruption (as we used to).  These together mean we refresh the sync db on corruption.  Also added some defensive dchecks.

To test this, I ripped out the test-only #ifdefs in SyncBackendHost so the tests use the real Initialize code path, and added a toolbox of stuff to control when we set initial sync ended bits during testing.

BUG=50965
TEST=DirectoryBackingStoreTest, ProfileSyncService* tests.

Review URL: http://codereview.chromium.org/3099001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55644 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 28 insertions, 5 deletions

diff --git a/chrome/browser/sync/syncable/directory_backing_store.cc b/chrome/browser/sync/syncable/directory_backing_store.cc
index 8dc939cd..7f82a73 100644
--- a/chrome/browser/sync/syncable/directory_backing_store.cc
+++ b/chrome/browser/sync/syncable/directory_backing_store.cc
@@ -14,6 +14,7 @@
 
 #include "base/file_util.h"
 #include "base/hash_tables.h"
+#include "base/histogram.h"
 #include "base/logging.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
@@ -283,11 +284,34 @@ bool DirectoryBackingStore::BeginLoad() {
   DCHECK(load_dbhandle_ == NULL);
   bool ret = OpenAndConfigureHandleHelper(&load_dbhandle_);
   if (ret)
-    return ret;
+    return true;
   // Something's gone wrong. Nuke the database and try again.
   LOG(ERROR) << "Sync database " << backing_filepath_.value()
-             << " corrupt.";
-  return false;
+             << " corrupt. Deleting and recreating.";
+  file_util::Delete(backing_filepath_, false);

+  bool failed_again = !OpenAndConfigureHandleHelper(&load_dbhandle_);
+
+  // Using failed_again here lets us distinguish from cases where corruption
+  // occurred even when re-opening a fresh directory (they'll go in a separate
+  // double weight histogram bucket).  Failing twice in a row means we disable
+  // sync, so it's useful to see this number separately.
+  int bucket = failed_again ? 2 : 1;
+#if defined(OS_WIN)
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedWin", bucket);
+#elif defined(OS_MACOSX)
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedMac", bucket);
+#else
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedNotWinMac", bucket);
+
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedLinux", bucket);
+#elif defined(OS_CHROMEOS)
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedCros", bucket);
+#else
+  UMA_HISTOGRAM_COUNTS_100("Sync.DirectoryOpenFailedOther", bucket);
+#endif  // OS_LINUX && !OS_CHROMEOS
+#endif  // OS_WIN
+  return !failed_again;
 }
 
 void DirectoryBackingStore::EndLoad() {
diff --git a/chrome/browser/sync/syncable/directory_backing_store_unittest.cc b/chrome/browser/sync/syncable/directory_backing_store_unittest.cc
index 7ec3d49..c158f9a 100644
--- a/chrome/browser/sync/syncable/directory_backing_store_unittest.cc
+++ b/chrome/browser/sync/syncable/directory_backing_store_unittest.cc
@@ -1019,8 +1019,7 @@ TEST_F(DirectoryBackingStoreTest, ModelTypeIds) {
   }
 }
 
-// TODO(tim): Disabled due to bug 48502.
-TEST_F(DirectoryBackingStoreTest, DISABLED_Corruption) {
+TEST_F(DirectoryBackingStoreTest, Corruption) {
   {
     scoped_ptr<DirectoryBackingStore> dbs(
         new DirectoryBackingStore(GetUsername(), GetDatabasePath()));