LevelDBDatabase::Compact compacts db (on disk) w/o requiring reopen.

This change writes (flushes) compacted data to disk resulting in
changes, which would previously only be flushed the next db close/open
cycle, to be written immediately.

BUG=329347

Review URL: https://codereview.chromium.org/397323003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284313 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/indexed_db/indexed_db_browsertest.cc

@@ -641,7 +641,7 @@ IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest,
   const int kTestFillBytes = 1024 * 1024 * 5;  // 5MB
   EXPECT_GT(after_filling, kTestFillBytes);
 
-  const int kTestCompactBytes = 1024 * 1024 * 1;  // 1MB
+  const int kTestCompactBytes = 1024 * 10;  // 10kB
   EXPECT_LT(after_deleting, kTestCompactBytes);
 }
 

content/browser/indexed_db/leveldb/leveldb_database.cc

@@ -395,6 +395,8 @@ void LevelDBDatabase::Compact(const base::StringPiece& start,
                               const base::StringPiece& stop) {
   const leveldb::Slice start_slice = MakeSlice(start);
   const leveldb::Slice stop_slice = MakeSlice(stop);
+  // NULL batch means just wait for earlier writes to be done
+  db_->Write(leveldb::WriteOptions(), NULL);
   db_->CompactRange(&start_slice, &stop_slice);
 }