Reland "Code Cleanup: Dedup usages of AccountManager's URL Context"

This is a reland of 94c42a4f

Original change's description:
> Code Cleanup: Dedup usages of AccountManager's URL Context
> 
> |InlineLoginHandlerChromeOS| and |ChromeOSOAuth2TokenServiceDelegate|
> use the system URL context because they 'know' that AccountManager is
> going to use the same. This is a leaky abstraction.
> 
> Add a method in AccountManager that returns its URL Request Context.
> This request context happens to be the system URL context for now.
> 
> Bug: 820046
> Change-Id: I668769167893c995f73df63acc575eb410c0f986
> Reviewed-on: https://chromium-review.googlesource.com/1088617
> Commit-Queue: Kush Sinha <sinhak@chromium.org>
> Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
> Reviewed-by: Lutz Justen <ljusten@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#566998}

Bug: 820046
Change-Id: I614beba63f15ebe3a3db9a267ef8d747a7728a50
Reviewed-on: https://chromium-review.googlesource.com/1105777Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Kush Sinha <sinhak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568778}

chrome/browser/chromeos/oauth2_token_service_delegate.cc

@@ -9,7 +9,6 @@
 
 #include "base/bind.h"
 #include "base/logging.h"
-#include "chrome/browser/browser_process.h"
 #include "chromeos/account_manager/account_manager.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 
@@ -140,13 +139,7 @@ void ChromeOSOAuth2TokenServiceDelegate::UpdateCredentials(
 
 net::URLRequestContextGetter*
 ChromeOSOAuth2TokenServiceDelegate::GetRequestContext() const {
-  // LSTs on Chrome are not channel/token bound for now and hence we can use
-  // the system request context.
-  // Note that we cannot use the Profile's request context since
-  // |AccountManager| acts outside the scope of Profiles.
-  // TODO(sinhak): Create a new |URLRequestContext| for |AccountManager| which
-  // conforms to token binding when those details are finalized.
-  return g_browser_process->system_request_context();
+  return account_manager_->GetUrlRequestContext();
 }
 
 OAuth2TokenServiceDelegate::LoadCredentialsState

chrome/browser/ui/webui/signin/inline_login_handler_chromeos.cc

@@ -120,10 +120,6 @@ void InlineLoginHandlerChromeOS::CompleteLogin(const base::ListValue* args) {
   const std::string& email = auth_data->FindKey("email")->GetString();
   CHECK(!email.empty());
 
-  // TODO(sinhak): Get URL Context from Account Manager when that is available.
-  net::URLRequestContextGetter* request_context =
-      g_browser_process->system_request_context();
-
   // TODO(sinhak): Do not depend on Profile unnecessarily.
   Profile* profile = Profile::FromWebUI(web_ui());
 
@@ -136,7 +132,8 @@ void InlineLoginHandlerChromeOS::CompleteLogin(const base::ListValue* args) {
           ->GetAccountManager(profile->GetPath().value());
 
   // SigninHelper deletes itself after its work is done.
-  new SigninHelper(profile, account_manager, request_context, gaia_id, email,
+  new SigninHelper(profile, account_manager,
+                   account_manager->GetUrlRequestContext(), gaia_id, email,
                    auth_code);
 }
 

chromeos/account_manager/account_manager.cc

@@ -352,6 +352,12 @@ void AccountManager::RemoveObserver(AccountManager::Observer* observer) {
 }
 
 net::URLRequestContextGetter* AccountManager::GetUrlRequestContext() {
+  // LSTs on Chrome are not channel/token bound for now and hence we can use
+  // the system request context.
+  // Note that we cannot use the Profile's request context since
+  // |AccountManager| acts outside the scope of Profiles.
+  // TODO(sinhak): Create a new |URLRequestContext| for |AccountManager| which
+  // conforms to token binding when those details are finalized.
   DCHECK(request_context_);
   return request_context_;
 }