Enable cookies per default in net. Add an API to disable them by default, and do that in Chrome

chrome/app/chrome_main_delegate.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/app/chrome_main_delegate.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop.h"
 #include "base/metrics/field_trial.h"
@@ skipping 16 matching lines @@
 #include "chrome/common/profiling.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/plugin/chrome_content_plugin_client.h"
 #include "chrome/renderer/chrome_content_renderer_client.h"
 #include "chrome/utility/chrome_content_utility_client.h"
 #include "content/common/content_counters.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
+#include "net/url_request/url_request.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_WIN)
 #include <algorithm>
 #include <atlbase.h>
 #include <malloc.h>
 #include "base/string_util.h"
 #include "base/win/registry.h"
 #include "chrome/browser/policy/policy_path_parser.h"
@@ skipping 340 matching lines @@
 #endif  // OS_POSIX
 
 struct MainFunction {
   const char* name;
   int (*function)(const content::MainFunctionParams&);
 };
 
 }  // namespace
 
 ChromeMainDelegate::ChromeMainDelegate() {
+  // Chrome disallows cookies per default. All code paths that need to use

[wtc, 2012/03/28 17:51:05]

Nit: per default => by default

[jochen (gone - plz use gerrit), 2012/03/29 18:33:24]

Done.

+  // cookies need to go through one of chrome's URLRequestContexts which have
+  // a ChromeNetworkDelegate attached that selectively allows cookies again.
+  net::URLRequest::SetDefaultCookiePolicyToBlock();

[jam, 2012/03/27 19:17:35]

why do this in chrome/app instead of chrome/browser? the former is for
chrome.exe while the latter is chrome.dll. and since they'll have different
copies of statics on windows, i think you'll need this in browser

[jochen (gone - plz use gerrit), 2012/03/29 18:33:24]

Done.

 }
 
 ChromeMainDelegate::~ChromeMainDelegate() {
 }
 
 bool ChromeMainDelegate::BasicStartupComplete(int* exit_code) {
 #if defined(OS_CHROMEOS)
   chromeos::BootTimesLoader::Get()->SaveChromeMainStats();
 #endif
 
@@ skipping 329 matching lines @@
 
 #if defined(USE_LINUX_BREAKPAD)
   // Needs to be called after we have chrome::DIR_USER_DATA.  BrowserMain sets
   // this up for the browser process in a different manner.
   InitCrashReporter();
 #endif
 
   InitializeChromeContentClient(process_type);
 }
 #endif  // OS_MACOSX