[Signin][Android] Add continue url to Logout request

Adds GaiaAuthFetcher::StartLogOutWithBlankContinueURL that specifies
a blank page as a continue URL for Logout requests. This continue URL
is necessary as sometimes Gaia redirects Logout requests to large pages
that exceed 1MB body limit for SimpleURLLoader::DownloadToString.

(cherry picked from commit 3d8eb95ae203c94c2455c542450a2371360cdf18)

Bug: b/134618807, 975887
Change-Id: Ie4d57ac959f8936077f98fce6a288ebf41122fc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656488
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#669836}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1663492
Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/branch-heads/3809@{#394}
Cr-Branched-From: d82dec1a818f378c464ba307ddd9c92133eac355-refs/heads/master@{#665002}

diff --git a/components/signin/core/browser/gaia_cookie_manager_service.cc b/components/signin/core/browser/gaia_cookie_manager_service.cc
index e28e2b5..c7275db 100644
--- a/components/signin/core/browser/gaia_cookie_manager_service.cc
+++ b/components/signin/core/browser/gaia_cookie_manager_service.cc

@@ -952,7 +952,15 @@
   RecordLogoutRequestState(LogoutRequestState::kStarted);
   gaia_auth_fetcher_ =
       signin_client_->CreateGaiaAuthFetcher(this, requests_.front().source());
-  gaia_auth_fetcher_->StartLogOut();
+  bool use_continue_url = false;
+#if defined(OS_ANDROID)
+  use_continue_url = base::FeatureList::IsEnabled(signin::kMiceFeature);
+#endif
+  if (use_continue_url) {
+    gaia_auth_fetcher_->StartLogOutWithBlankContinueURL();
+  } else {
+    gaia_auth_fetcher_->StartLogOut();
+  }
 }
 
 void GaiaCookieManagerService::StartFetchingListAccounts() {

diff --git a/google_apis/gaia/gaia_auth_fetcher.cc b/google_apis/gaia/gaia_auth_fetcher.cc
index e39e285..3d621690 100644
--- a/google_apis/gaia/gaia_auth_fetcher.cc
+++ b/google_apis/gaia/gaia_auth_fetcher.cc

@@ -228,6 +228,8 @@
       list_accounts_gurl_(
           GaiaUrls::GetInstance()->ListAccountsURLWithSource(source_)),
       logout_gurl_(GaiaUrls::GetInstance()->LogOutURLWithSource(source_)),
+      logout_with_continue_gurl_(
+          GaiaUrls::GetInstance()->LogOutURLWithSourceAndContinueURL(source_)),
       get_check_connection_info_url_(
           GaiaUrls::GetInstance()->GetCheckConnectionInfoURLWithSource(
               source_)) {}
@@ -807,6 +809,14 @@
 }
 
 void GaiaAuthFetcher::StartLogOut() {
+  StartLogOutInternal(logout_gurl_);
+}
+
+void GaiaAuthFetcher::StartLogOutWithBlankContinueURL() {
+  StartLogOutInternal(logout_with_continue_gurl_);
+}
+
+void GaiaAuthFetcher::StartLogOutInternal(const GURL& logout_gurl) {
   DCHECK(!fetch_pending_) << "Tried to fetch two things at once!";
 
   net::NetworkTrafficAnnotationTag traffic_annotation =
@@ -836,7 +846,7 @@
             }
           }
         })");
-  CreateAndStartGaiaFetcher(std::string(), std::string(), logout_gurl_,
+  CreateAndStartGaiaFetcher(std::string(), std::string(), logout_gurl,
                             net::LOAD_NORMAL, traffic_annotation);
 }
 
@@ -1133,7 +1143,7 @@
     OnOAuth2RevokeTokenFetched(data, net_error, response_code);
   } else if (url == list_accounts_gurl_) {
     OnListAccountsFetched(data, net_error, response_code);
-  } else if (url == logout_gurl_) {
+  } else if (url == logout_gurl_ || url == logout_with_continue_gurl_) {
     OnLogOutFetched(data, net_error, response_code);
   } else if (url == get_check_connection_info_url_) {
     OnGetCheckConnectionInfoFetched(data, net_error, response_code);

diff --git a/google_apis/gaia/gaia_auth_fetcher.h b/google_apis/gaia/gaia_auth_fetcher.h
index 289c9f2..ae48d42d 100644
--- a/google_apis/gaia/gaia_auth_fetcher.h
+++ b/google_apis/gaia/gaia_auth_fetcher.h

@@ -168,6 +168,10 @@
   // Starts a request to log out the accounts in the GAIA cookie.
   void StartLogOut();
 
+  // Starts a request to log out the accounts in the GAIA cookie. Uses Logout
+  // endpoint with continue URL.
+  void StartLogOutWithBlankContinueURL();
+
   // Starts a request to get the list of URLs to check for connection info.
   // Returns token/URL pairs to check, and the resulting status can be given to
   // /MergeSession requests.
@@ -267,6 +271,9 @@
   static const char kOAuth2BearerHeaderFormat[];
   static const char kOAuthMultiBearerHeaderFormat[];
 
+  // Starts logout flow with an explicit GURL.
+  void StartLogOutInternal(const GURL& logout_gurl);
+
   void OnURLLoadComplete(std::unique_ptr<std::string> response_body);
 
   void OnOAuth2TokenPairFetched(const std::string& data,
@@ -373,6 +380,7 @@
   const GURL oauth_multilogin_gurl_;
   const GURL list_accounts_gurl_;
   const GURL logout_gurl_;
+  const GURL logout_with_continue_gurl_;
   const GURL get_check_connection_info_url_;
 
   // While a fetch is going on:

diff --git a/google_apis/gaia/gaia_urls.cc b/google_apis/gaia/gaia_urls.cc
index ffce9b4..c464feb 100644
--- a/google_apis/gaia/gaia_urls.cc
+++ b/google_apis/gaia/gaia_urls.cc

@@ -31,6 +31,7 @@
 const char kSigninChromeSyncDice[] = "signin/chrome/sync?ssp=1";
 const char kServiceLoginAuthUrlSuffix[] = "ServiceLoginAuth";
 const char kServiceLogoutUrlSuffix[] = "Logout";
+const char kContinueUrlForLogoutSuffix[] = "chrome/blank.html";
 const char kGetUserInfoUrlSuffix[] = "GetUserInfo";
 const char kTokenAuthUrlSuffix[] = "TokenAuth";
 const char kMergeSessionUrlSuffix[] = "MergeSession";
@@ -117,6 +118,7 @@
   signin_chrome_sync_dice_ = gaia_url_.Resolve(kSigninChromeSyncDice);
   service_login_auth_url_ = gaia_url_.Resolve(kServiceLoginAuthUrlSuffix);
   service_logout_url_ = gaia_url_.Resolve(kServiceLogoutUrlSuffix);
+  continue_url_for_logout_ = gaia_url_.Resolve(kContinueUrlForLogoutSuffix);
   get_user_info_url_ = gaia_url_.Resolve(kGetUserInfoUrlSuffix);
   token_auth_url_ = gaia_url_.Resolve(kTokenAuthUrlSuffix);
   merge_session_url_ = gaia_url_.Resolve(kMergeSessionUrlSuffix);
@@ -297,6 +299,16 @@
                               base::StringPrintf("?source=%s", source.c_str()));
 }
 
+GURL GaiaUrls::LogOutURLWithSourceAndContinueURL(const std::string& source) {
+  std::string params =
+      source.empty()
+          ? base::StringPrintf("?continue=%s",
+                               continue_url_for_logout_.spec().c_str())
+          : base::StringPrintf("?source=%s&continue=%s", source.c_str(),
+                               continue_url_for_logout_.spec().c_str());
+  return service_logout_url_.Resolve(params);
+}
+
 GURL GaiaUrls::GetCheckConnectionInfoURLWithSource(const std::string& source) {
   return source.empty()
       ? get_check_connection_info_url_

diff --git a/google_apis/gaia/gaia_urls.h b/google_apis/gaia/gaia_urls.h
index f011761..68455c9 100644
--- a/google_apis/gaia/gaia_urls.h
+++ b/google_apis/gaia/gaia_urls.h

@@ -52,6 +52,7 @@
 
   GURL ListAccountsURLWithSource(const std::string& source);
   GURL LogOutURLWithSource(const std::string& source);
+  GURL LogOutURLWithSourceAndContinueURL(const std::string& source);
   GURL GetCheckConnectionInfoURLWithSource(const std::string& source);
 
  private:
@@ -72,6 +73,7 @@
   GURL signin_chrome_sync_dice_;
   GURL service_login_auth_url_;
   GURL service_logout_url_;
+  GURL continue_url_for_logout_;
   GURL get_user_info_url_;
   GURL token_auth_url_;
   GURL merge_session_url_;