Increase page size for SyncData DB from 4K to maximum supported 32K

sync/syncable/on_disk_directory_backing_store.cc

Index: sync/syncable/on_disk_directory_backing_store.cc
diff --git a/sync/syncable/on_disk_directory_backing_store.cc b/sync/syncable/on_disk_directory_backing_store.cc
index 1bebf9aff2f79557fe30702c98b957e752726fe2..706f7c2e3e0bcfc438ec37dfccc62c30f94f0d5d 100644
--- a/sync/syncable/on_disk_directory_backing_store.cc
+++ b/sync/syncable/on_disk_directory_backing_store.cc
@@ -29,7 +29,11 @@ OnDiskDirectoryBackingStore::OnDiskDirectoryBackingStore(
       allow_failure_for_test_(false),
       backing_filepath_(backing_filepath) {
   db_->set_exclusive_locking();
-  db_->set_page_size(4096);
+  if (IsSyncBackingDatabase32KEnabled()) {
+    db_->set_page_size(32768);
+  } else {
+    db_->set_page_size(4096);
+  }
 }
 
 OnDiskDirectoryBackingStore::~OnDiskDirectoryBackingStore() { }
@@ -85,7 +89,11 @@ DirOpenResult OnDiskDirectoryBackingStore::Load(
   // brittle.  Either have a helper to set these up (or generate a new
   // connection), or add something like Reset() to sql::Connection.
   db_->set_exclusive_locking();
-  db_->set_page_size(4096);
+  if (IsSyncBackingDatabase32KEnabled()) {

[stanisc, 2015/03/17 16:02:41]

This code fragment is repeated 4 times. Consider making it a function in the
base class.
Or I think it should be enough to simply place this code once in the base class
constructor.

[Gang Wu, 2015/03/17 23:52:46]

Done.

+    db_->set_page_size(32768);
+  } else {
+    db_->set_page_size(4096);
+  }
   db_->set_histogram_tag("SyncDirectory");
   base::DeleteFile(backing_filepath_, false);