Request the Identity API's Uber Token without a Channel ID

chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc

Index: chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc
diff --git a/chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc b/chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc
index d98d0fc84960fa841553a026652bdcab56e002e6..4eb711c4ec4611c64e6e7c1188dde44c756d578d 100644
--- a/chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc
+++ b/chrome/browser/extensions/api/identity/gaia_web_auth_flow.cc
@@ -18,6 +18,9 @@
 #include "google_apis/gaia/gaia_constants.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "net/base/escape.h"
+#include "net/ssl/channel_id_service.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_getter.h"
 
 namespace extensions {
 
@@ -91,19 +94,79 @@ GaiaWebAuthFlow::~GaiaWebAuthFlow() {
 }
 
 void GaiaWebAuthFlow::Start() {
+  main_context_ = profile_->GetRequestContext();
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&GaiaWebAuthFlow::StartOnIOThread, base::Unretained(this)));
+}
+
+void GaiaWebAuthFlow::StartOnIOThread() {
+  net::URLRequestContext* base_context = main_context_->GetURLRequestContext();
+  // Create a temporary request context for the Uber Token Fetch that doesn't
+  // have a Channel ID. This way, the Uber Token will not be channel bound and
+  // will be useable for the MergeSession call that will take place in the app's
+  // request context.
+  ProfileIOData::AppRequestContext* context =
+      new ProfileIOData::AppRequestContext;
+  ubertoken_request_context_.reset(context);
+
+  context->CopyFrom(base_context);
+  context->SetChannelIDService(nullptr);
+
+  // Merely setting the Channel ID Service isn't enough, we also have to build a
+  // new HttpNetworkSession.
+  std::unique_ptr<net::HttpCache::BackendFactory> app_backend =
+      net::HttpCache::DefaultBackend::InMemory(0);
+  net::HttpNetworkSession::Params network_params =
+      *base_context->GetNetworkSessionParams();
+  network_params.channel_id_service = nullptr;
+  std::unique_ptr<net::HttpNetworkSession> http_network_session(
+      new net::HttpNetworkSession(network_params));
+  std::unique_ptr<net::HttpCache> app_http_cache(
+      new net::HttpCache(http_network_session.get(),
+                         std::move(app_backend), true));
+
+  context->SetHttpNetworkSession(
+      std::move(http_network_session));
+  context->SetHttpTransactionFactory(std::move(app_http_cache));
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&GaiaWebAuthFlow::StartUberTokenFetch,
+                 base::Unretained(this)));
+}
+
+void GaiaWebAuthFlow::StartUberTokenFetch() {
   ProfileOAuth2TokenService* token_service =
       ProfileOAuth2TokenServiceFactory::GetForProfile(profile_);
+  context_getter_ = new net::TrivialURLRequestContextGetter(
+      ubertoken_request_context_.get(),
+      main_context_->GetNetworkTaskRunner());
   ubertoken_fetcher_.reset(new UbertokenFetcher(token_service,
                                                 this,
                                                 GaiaConstants::kChromeSource,
-                                                profile_->GetRequestContext()));
+                                                context_getter_.get()));
   ubertoken_fetcher_->StartFetchingToken(account_id_);
 }
 
+void GaiaWebAuthFlow::CleanupRequestContextOnIOThread() {
+  ubertoken_request_context_.reset();
+}
+
 void GaiaWebAuthFlow::OnUbertokenSuccess(const std::string& token) {
   TRACE_EVENT_ASYNC_STEP_PAST0(
       "identity", "GaiaWebAuthFlow", this, "OnUbertokenSuccess");
 
+  // The temporary request context isn't required after the Uber Token request
+  // completes. It needs to be deleted on the IO Thread, so do that here.
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&GaiaWebAuthFlow::CleanupRequestContextOnIOThread,
+                 base::Unretained(this)));
+
   const char kMergeSessionQueryFormat[] = "?uberauth=%s&"
                                           "continue=%s&"
                                           "source=appsv2";
@@ -127,6 +190,14 @@ void GaiaWebAuthFlow::OnUbertokenFailure(const GoogleServiceAuthError& error) {
                                "error",
                                error.ToString());
 
+  // The temporary request context isn't required after the Uber Token request
+  // completes. It needs to be deleted on the IO Thread, so do that here.
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&GaiaWebAuthFlow::CleanupRequestContextOnIOThread,
+                 base::Unretained(this)));
+
   DVLOG(1) << "OnUbertokenFailure: " << error.error_message();
   delegate_->OnGaiaFlowFailure(
       GaiaWebAuthFlow::SERVICE_AUTH_ERROR, error, std::string());