Instantiate the WebIDBFactoryImpl lazily, and call setIDBFactory

webkit/support/test_webkit_platform_support.cc

Index: webkit/support/test_webkit_platform_support.cc
===================================================================
--- webkit/support/test_webkit_platform_support.cc	(revision 177172)
+++ webkit/support/test_webkit_platform_support.cc	(working copy)
@@ -346,8 +346,7 @@
 // to a real profile directory during IPC.
 class TestWebIDBFactory : public WebKit::WebIDBFactory {
  public:
-  TestWebIDBFactory()
-      : factory_(WebKit::WebIDBFactory::create()) {
+  TestWebIDBFactory() {
     // Create a new temp directory for Indexed DB storage, specific to this
     // factory. If this fails, WebKit uses in-memory storage.
     if (!indexed_db_dir_.CreateUniqueTempDir()) {
@@ -357,12 +356,16 @@
     }
     data_dir_ = webkit_support::GetAbsoluteWebStringFromUTF8Path(
       indexed_db_dir_.path().AsUTF8Unsafe());
+
+    // Lazily construct factory_ so that it gets allocated on the thread where
+    // it will be used.  TestWebIDBFactory gets allocated on the main thread.
   }
 
   virtual void getDatabaseNames(WebKit::WebIDBCallbacks* callbacks,
                                 const WebKit::WebSecurityOrigin& origin,
                                 WebKit::WebFrame* frame,
                                 const WebString& dataDir) {
+    EnsureFactory();
     factory_->getDatabaseNames(callbacks, origin, frame,
                                dataDir.isEmpty() ? data_dir_ : dataDir);
   }
@@ -375,9 +378,10 @@
                     const WebKit::WebSecurityOrigin& origin,
                     WebKit::WebFrame* frame,
                     const WebString& dataDir) {
-      factory_->open(name, version, transaction_id, callbacks,
-                     databaseCallbacks, origin, frame,
-                     dataDir.isEmpty() ? data_dir_ : dataDir);
+    EnsureFactory();
+    factory_->open(name, version, transaction_id, callbacks,
+                   databaseCallbacks, origin, frame,
+                   dataDir.isEmpty() ? data_dir_ : dataDir);
   }
 
   virtual void deleteDatabase(const WebString& name,
@@ -385,10 +389,16 @@
                               const WebKit::WebSecurityOrigin& origin,
                               WebKit::WebFrame* frame,
                               const WebString& dataDir) {
+    EnsureFactory();
     factory_->deleteDatabase(name, callbacks, origin, frame,
                              dataDir.isEmpty() ? data_dir_ : dataDir);
   }
  private:
+  void EnsureFactory() {
+    if (!factory_)
+      factory_.reset(WebKit::WebIDBFactory::create());

[jsbell, 2013/01/16 23:19:28]

I don't know if this is plausible, but it would be nice to capture the creation
thread and DCHECK() that later calls to EnsureFactory() are occurring on the
same thread. Possibly overkill for test code, but would e.g. make mysterious DRT
failures less mysterious.

+  }
+
   scoped_ptr<WebIDBFactory> factory_;
   base::ScopedTempDir indexed_db_dir_;
   WebString data_dir_;