Instantiate the WebIDBFactoryImpl lazily, and call setIDBFactory

webkit/support/test_webkit_platform_support.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/support/test_webkit_platform_support.h"
 
 #include "base/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
@@ skipping 328 matching lines @@
 TestWebKitPlatformSupport::createLocalStorageNamespace(
     const WebKit::WebString& path, unsigned quota) {
   return dom_storage_system_.CreateLocalStorageNamespace();
 }
 
 // Wrap a WebKit::WebIDBFactory to rewrite the data directory to
 // a scoped temp directory. In multiprocess Chromium this is rewritten
 // 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()) {
       LOG(WARNING) << "Failed to create a temp dir for Indexed DB, "
           "using in-memory storage.";
       DCHECK(indexed_db_dir_.path().empty());
     }
     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);
   }
 
   virtual void open(const WebString& name,
                     long long version,
                     long long transaction_id,
                     WebKit::WebIDBCallbacks* callbacks,
                     WebKit::WebIDBDatabaseCallbacks* databaseCallbacks,
                     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,
                               WebKit::WebIDBCallbacks* callbacks,
                               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_;
 };
 
 WebKit::WebIDBFactory* TestWebKitPlatformSupport::idbFactory() {
   return new TestWebIDBFactory();
 }
 
 #if defined(OS_WIN) || defined(OS_MACOSX)
@@ skipping 188 matching lines @@
   return 0;
 }
 
 WebKit::WebGestureCurve* TestWebKitPlatformSupport::createFlingAnimationCurve(
     int device_source,
     const WebKit::WebFloatPoint& velocity,
     const WebKit::WebSize& cumulative_scroll) {
   // Caller will retain and release.
   return new WebGestureCurveMock(velocity, cumulative_scroll);
 }