Fix a race in DatabaseManager::manager.

Source/modules/webdatabase/DatabaseManager.cpp

Index: Source/modules/webdatabase/DatabaseManager.cpp
diff --git a/Source/modules/webdatabase/DatabaseManager.cpp b/Source/modules/webdatabase/DatabaseManager.cpp
index a6bfc1a76ac64067876cf0fc74d1a7dcb415dfdf..78042ec8595756bc7cbe6fe334e32294c45a7b5e 100644
--- a/Source/modules/webdatabase/DatabaseManager.cpp
+++ b/Source/modules/webdatabase/DatabaseManager.cpp
@@ -49,12 +49,7 @@ namespace WebCore {
 
 DatabaseManager& DatabaseManager::manager()
 {
-    static DatabaseManager* dbManager = 0;
-    // FIXME: The following is vulnerable to a race between threads. Need to
-    // implement a thread safe on-first-use static initializer.
-    if (!dbManager)
-        dbManager = new DatabaseManager();
-
+    AtomicallyInitializedStatic(DatabaseManager*, dbManager = new DatabaseManager);

[eseidel, 2014/05/29 07:03:37]

I didn't know this existed, crazy.

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

     return *dbManager;
 }