IndexedDB: Add --level-db flag, and pipe through to WebIDBFactory::open.

content/common/content_switches.cc

Index: content/common/content_switches.cc
diff --git a/content/common/content_switches.cc b/content/common/content_switches.cc
index b70bc800bf6bb48989c89140467affa283fe0d4a..117e4e78495b9b17e91c3176a88042875c77a604 100644
--- a/content/common/content_switches.cc
+++ b/content/common/content_switches.cc
@@ -96,6 +96,9 @@ const char kGpuProcess[]                    = "gpu-process";
 // Causes the GPU process to display a dialog on launch.
 const char kGpuStartupDialog[]              = "gpu-startup-dialog";
 
+// Use LevelDB as back-end for Indexed Database API.
+const char kLevelDBIndexedDatabase[]        = "indexeddb-use-leveldb";
+
 // Load an NPAPI plugin from the specified path.
 const char kLoadPlugin[]                    = "load-plugin";