Allow SessionBackend::Init() to occur just-in-time in production builds.

chrome/browser/sessions/base_session_service.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 "chrome/browser/sessions/base_session_service.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/pickle.h"
@@ skipping 73 matching lines @@
     // We should never be created when incognito.
     DCHECK(!profile->IsOffTheRecord());
     const CommandLine* command_line = CommandLine::ForCurrentProcess();
     save_post_data_ =
         command_line->HasSwitch(switches::kEnableRestoreSessionState);
   }
   backend_ = new SessionBackend(type,
       profile_ ? profile_->GetPath() : path_);
   DCHECK(backend_.get());
 
-  RunTaskOnBackendThread(FROM_HERE,
-                         base::Bind(&SessionBackend::Init, backend_));
+  if (!RunningInProduction()) {
+    // We seem to be running as part of a test, in which case we need
+    // to explicitly initialize the backend.  In production, the
+    // backend will automatically initialize itself just in time.
+    //
+    // Note that it's important not to initialize too early in
+    // production; this can cause e.g. http://crbug.com/110785.
+    backend_->Init();
+  }
 }
 
 BaseSessionService::~BaseSessionService() {
 }
 
 void BaseSessionService::DeleteLastSession() {
   RunTaskOnBackendThread(
       FROM_HERE,
       base::Bind(&SessionBackend::DeleteLastSession, backend()));
 }
@@ skipping 209 matching lines @@
     CancelableRequestConsumerBase* consumer) {
   scoped_refptr<InternalGetCommandsRequest> request_wrapper(request);
   AddRequest(request, consumer);
   RunTaskOnBackendThread(
       FROM_HERE,
       base::Bind(&SessionBackend::ReadLastSessionCommands, backend(),
                  request_wrapper));
   return request->handle();
 }
 
+bool BaseSessionService::RunningInProduction() const {
+  return profile_ && BrowserThread::IsMessageLoopValid(BrowserThread::FILE);
+}
+
 bool BaseSessionService::RunTaskOnBackendThread(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
-  if (profile_ && BrowserThread::IsMessageLoopValid(BrowserThread::FILE)) {
+  if (RunningInProduction()) {
     return BrowserThread::PostTask(BrowserThread::FILE, from_here, task);
   } else {
     // Fall back to executing on the main thread if the file thread
     // has gone away (around shutdown time) or if we're running as
     // part of a unit test that does not set profile_.
     task.Run();
     return true;
   }
 }