Fix issues related to request and context object lifespan (issue #1037, issue #1044).

- Simplify and document the relationship between the various context object types. See browser_context.h for a description of the new relationships.
- cefclient: Add `request-context-per-browser` command-line flag for testing multiple CefRequestContext instances.
- cefclient: Add a CefURLRequest example.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@2032 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/browser_context.cc

@@ -0,0 +1,52 @@
+// Copyright (c) 2015 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 "libcef/browser/browser_context.h"
+#include "libcef/browser/content_browser_client.h"
+
+#include "base/logging.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "components/user_prefs/user_prefs.h"
+#include "content/public/browser/browser_thread.h"
+
+#ifndef NDEBUG
+base::AtomicRefCount CefBrowserContext::DebugObjCt = 0;
+#endif
+
+CefBrowserContext::CefBrowserContext()
+    : resource_context_(new CefResourceContext) {
+  BrowserContextDependencyManager::GetInstance()->CreateBrowserContextServices(
+      this);
+
+  // Spell checking support and possibly other subsystems retrieve the
+  // PrefService associated with a BrowserContext via UserPrefs::Get().
+  PrefService* pref_service = CefContentBrowserClient::Get()->pref_service();
+  DCHECK(pref_service);
+  user_prefs::UserPrefs::Set(this, pref_service);
+
+#ifndef NDEBUG
+  base::AtomicRefCountInc(&DebugObjCt);
+#endif
+}
+
+CefBrowserContext::~CefBrowserContext() {
+  if (resource_context_.get()) {
+    // Destruction of the ResourceContext will trigger destruction of all
+    // associated URLRequests.
+    content::BrowserThread::DeleteSoon(
+        content::BrowserThread::IO, FROM_HERE, resource_context_.release());
+  }
+
+  // Remove any BrowserContextKeyedServiceFactory associations.
+  BrowserContextDependencyManager::GetInstance()->DestroyBrowserContextServices(
+      this);
+
+#ifndef NDEBUG
+  base::AtomicRefCountDec(&DebugObjCt);
+#endif
+}
+
+content::ResourceContext* CefBrowserContext::GetResourceContext() {
+  return resource_context_.get();
+}