[GCM] Fetching OAuth2 tokens periodically in account tracker

BUG=374969
R=zea@chromium.org

Review URL: https://codereview.chromium.org/631343002

Cr-Commit-Position: refs/heads/master@{#303340}

3 files changed, 185 insertions, 23 deletions

diff --git a/chrome/browser/services/gcm/gcm_account_tracker.cc b/chrome/browser/services/gcm/gcm_account_tracker.cc
index a2cdba0..0521688 100644
--- a/chrome/browser/services/gcm/gcm_account_tracker.cc
+++ b/chrome/browser/services/gcm/gcm_account_tracker.cc
@@ -15,11 +15,18 @@
 namespace gcm {
 
 namespace {
+
+// Scopes needed by the OAuth2 access tokens.
 const char kGCMGroupServerScope[] = "https://www.googleapis.com/auth/gcm";
 const char kGCMCheckinServerScope[] =
     "https://www.googleapis.com/auth/android_checkin";
+// Name of the GCM account tracker for the OAuth2TokenService.
 const char kGCMAccountTrackerName[] = "gcm_account_tracker";
+// Minimum token validity when sending to GCM groups server.
 const int64 kMinimumTokenValidityMs = 500;
+// Token reporting interval, when no account changes are detected.
+const int64 kTokenReportingIntervalMs = 12 * 60 * 60 * 1000;  // 12 hours in ms.
+
 }  // namespace
 
 GCMAccountTracker::AccountInfo::AccountInfo(const std::string& email,
@@ -36,7 +43,8 @@ GCMAccountTracker::GCMAccountTracker(
     : OAuth2TokenService::Consumer(kGCMAccountTrackerName),
       account_tracker_(account_tracker.release()),
       driver_(driver),
-      shutdown_called_(false) {
+      shutdown_called_(false),
+      reporting_weak_ptr_factory_(this) {
 }
 
 GCMAccountTracker::~GCMAccountTracker() {
@@ -56,11 +64,6 @@ void GCMAccountTracker::Start() {
   driver_->AddConnectionObserver(this);
 
   std::vector<gaia::AccountIds> accounts = account_tracker_->GetAccounts();
-  if (accounts.empty()) {
-    CompleteCollectingTokens();
-    return;
-  }
-
   for (std::vector<gaia::AccountIds>::const_iterator iter = accounts.begin();
        iter != accounts.end();
        ++iter) {
@@ -70,7 +73,22 @@ void GCMAccountTracker::Start() {
     }
   }
 
-  GetAllNeededTokens();
+  if (IsTokenReportingRequired())
+    ReportTokens();
+  else
+    ScheduleReportTokens();
+}
+
+void GCMAccountTracker::ScheduleReportTokens() {
+  DVLOG(1) << "Deferring the token reporting for: "
+           << GetTimeToNextTokenReporting().InSeconds() << " seconds.";
+
+  reporting_weak_ptr_factory_.InvalidateWeakPtrs();
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&GCMAccountTracker::ReportTokens,
+                 reporting_weak_ptr_factory_.GetWeakPtr()),
+      GetTimeToNextTokenReporting());
 }
 
 void GCMAccountTracker::OnAccountAdded(const gaia::AccountIds& ids) {
@@ -115,7 +133,7 @@ void GCMAccountTracker::OnGetTokenSuccess(
   }
 
   DeleteTokenRequest(request);
-  CompleteCollectingTokens();
+  ReportTokens();
 }
 
 void GCMAccountTracker::OnGetTokenFailure(
@@ -137,21 +155,22 @@ void GCMAccountTracker::OnGetTokenFailure(
   }
 
   DeleteTokenRequest(request);
-  CompleteCollectingTokens();
+  ReportTokens();
 }
 
 void GCMAccountTracker::OnConnected(const net::IPEndPoint& ip_endpoint) {
-  if (SanitizeTokens())
-    GetAllNeededTokens();
+  if (IsTokenReportingRequired())
+    ReportTokens();
 }
 
 void GCMAccountTracker::OnDisconnected() {
   // We are disconnected, so no point in trying to work with tokens.
 }
 
-void GCMAccountTracker::CompleteCollectingTokens() {
+void GCMAccountTracker::ReportTokens() {
+  SanitizeTokens();
   // Make sure all tokens are valid.
-  if (SanitizeTokens()) {
+  if (IsTokenFetchingRequired()) {
     GetAllNeededTokens();
     return;
   }
@@ -198,13 +217,14 @@ void GCMAccountTracker::CompleteCollectingTokens() {
   if (!account_tokens.empty() || account_removed) {
     DVLOG(1) << "Reporting the tokens to driver: " << account_tokens.size();
     driver_->SetAccountTokens(account_tokens);
+    driver_->SetLastTokenFetchTime(base::Time::Now());
+    ScheduleReportTokens();
   } else {
     DVLOG(1) << "No tokens and nothing removed. Skipping callback.";
   }
 }
 
-bool GCMAccountTracker::SanitizeTokens() {
-  bool tokens_needed = false;
+void GCMAccountTracker::SanitizeTokens() {
   for (AccountInfos::iterator iter = account_infos_.begin();
        iter != account_infos_.end();
        ++iter) {
@@ -216,12 +236,43 @@ bool GCMAccountTracker::SanitizeTokens() {
       iter->second.state = TOKEN_NEEDED;
       iter->second.expiration_time = base::Time();
     }
+  }
+}
+
+bool GCMAccountTracker::IsTokenReportingRequired() const {
+  if (GetTimeToNextTokenReporting() == base::TimeDelta())
+    return true;
+
+  bool reporting_required = false;
+  for (AccountInfos::const_iterator iter = account_infos_.begin();
+       iter != account_infos_.end();
+       ++iter) {
+    if (iter->second.state == ACCOUNT_REMOVED)
+      reporting_required = true;
+  }
 
+  return reporting_required;
+}
+
+bool GCMAccountTracker::IsTokenFetchingRequired() const {
+  bool token_needed = false;
+  for (AccountInfos::const_iterator iter = account_infos_.begin();
+       iter != account_infos_.end();
+       ++iter) {
     if (iter->second.state == TOKEN_NEEDED)
-      tokens_needed = true;
+      token_needed = true;
   }
 
-  return tokens_needed;
+  return token_needed;
+}
+
+base::TimeDelta GCMAccountTracker::GetTimeToNextTokenReporting() const {
+  base::TimeDelta time_till_next_reporting =
+      driver_->GetLastTokenFetchTime() +
+      base::TimeDelta::FromMilliseconds(kTokenReportingIntervalMs) -
+      base::Time::Now();
+  return time_till_next_reporting < base::TimeDelta() ?
+             base::TimeDelta() : time_till_next_reporting;
 }
 
 void GCMAccountTracker::DeleteTokenRequest(
@@ -235,6 +286,9 @@ void GCMAccountTracker::DeleteTokenRequest(
 void GCMAccountTracker::GetAllNeededTokens() {
   // Only start fetching tokens if driver is running, they have a limited
   // validity time and GCM connection is a good indication of network running.
+  // If the GetAllNeededTokens was called as part of periodic schedule, it may
+  // not have network. In that case the next network change will trigger token
+  // fetching.
   if (!driver_->IsConnected())
     return;
 
@@ -282,7 +336,7 @@ void GCMAccountTracker::OnAccountSignedOut(const gaia::AccountIds& ids) {
 
   iter->second.access_token.clear();
   iter->second.state = ACCOUNT_REMOVED;
-  CompleteCollectingTokens();
+  ReportTokens();
 }
 
 OAuth2TokenService* GCMAccountTracker::GetTokenService() {
diff --git a/chrome/browser/services/gcm/gcm_account_tracker.h b/chrome/browser/services/gcm/gcm_account_tracker.h
index 0b1c5e8..39f357e 100644
--- a/chrome/browser/services/gcm/gcm_account_tracker.h
+++ b/chrome/browser/services/gcm/gcm_account_tracker.h
@@ -14,12 +14,21 @@
 #include "google_apis/gaia/account_tracker.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
+namespace base {
+class Time;
+}
+
 namespace gcm {
 
 class GCMDriver;
 
 // Class for reporting back which accounts are signed into. It is only meant to
 // be used when the user is signed into sync.
+//
+// This class makes a check for tokens periodically, to make sure the user is
+// still logged into the profile, so that in the case that the user is not, we
+// can immediately report that to the GCM and stop messages addressed to that
+// user from ever reaching Chrome.
 class GCMAccountTracker : public gaia::AccountTracker::Observer,
                           public OAuth2TokenService::Consumer,
                           public GCMConnectionObserver {
@@ -76,6 +85,8 @@ class GCMAccountTracker : public gaia::AccountTracker::Observer,
   }
 
  private:
+  friend class GCMAccountTrackerTest;
+
   // Maps account keys to account states. Keyed by account_ids as used by
   // OAuth2TokenService.
   typedef std::map<std::string, AccountInfo> AccountInfos;
@@ -97,13 +108,22 @@ class GCMAccountTracker : public gaia::AccountTracker::Observer,
   void OnConnected(const net::IPEndPoint& ip_endpoint) override;
   void OnDisconnected() override;
 
+  // Schedules token reporting.
+  void ScheduleReportTokens();
   // Report the list of accounts with OAuth2 tokens back using the |callback_|
   // function. If there are token requests in progress, do nothing.
-  void CompleteCollectingTokens();
+  void ReportTokens();
   // Verify that all of the tokens are ready to be passed down to the GCM
   // Driver, e.g. none of them has expired or is missing. Returns true if not
   // all tokens are valid and a fetching yet more tokens is required.
-  bool SanitizeTokens();
+  void SanitizeTokens();
+  // Indicates whether token reporting is required, either because it is due, or
+  // some of the accounts were removed.
+  bool IsTokenReportingRequired() const;
+  // Indicates whether there are tokens that still need fetching.
+  bool IsTokenFetchingRequired() const;
+  // Gets the time until next token reporting.
+  base::TimeDelta GetTimeToNextTokenReporting() const;
   // Deletes a token request. Should be called from OnGetTokenSuccess(..) or
   // OnGetTokenFailure(..).
   void DeleteTokenRequest(const OAuth2TokenService::Request* request);
@@ -133,6 +153,10 @@ class GCMAccountTracker : public gaia::AccountTracker::Observer,
 
   ScopedVector<OAuth2TokenService::Request> pending_token_requests_;
 
+  // Creates weak pointers used to postpone reporting tokens. See
+  // ScheduleReportTokens.
+  base::WeakPtrFactory<GCMAccountTracker> reporting_weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(GCMAccountTracker);
 };
 
diff --git a/chrome/browser/services/gcm/gcm_account_tracker_unittest.cc b/chrome/browser/services/gcm/gcm_account_tracker_unittest.cc
index 2211d76..eb8030a 100644
--- a/chrome/browser/services/gcm/gcm_account_tracker_unittest.cc
+++ b/chrome/browser/services/gcm/gcm_account_tracker_unittest.cc
@@ -8,8 +8,6 @@
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop.h"
-#include "base/run_loop.h"
 #include "components/gcm_driver/fake_gcm_driver.h"
 #include "google_apis/gaia/fake_identity_provider.h"
 #include "google_apis/gaia/fake_oauth2_token_service.h"
@@ -76,6 +74,8 @@ class CustomFakeGCMDriver : public FakeGCMDriver {
   void AddConnectionObserver(GCMConnectionObserver* observer) override;
   void RemoveConnectionObserver(GCMConnectionObserver* observer) override;
   bool IsConnected() const override { return connected_; }
+  base::Time GetLastTokenFetchTime() override;
+  void SetLastTokenFetchTime(const base::Time& time) override;
 
   // Test results and helpers.
   void SetConnected(bool connected);
@@ -98,6 +98,7 @@ class CustomFakeGCMDriver : public FakeGCMDriver {
   GCMConnectionObserver* last_connection_observer_;
   GCMConnectionObserver* removed_connection_observer_;
   net::IPEndPoint ip_endpoint_;
+  base::Time last_token_fetch_time_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomFakeGCMDriver);
 };
@@ -141,6 +142,15 @@ void CustomFakeGCMDriver::ResetResults() {
   removed_connection_observer_ = NULL;
 }
 
+
+base::Time CustomFakeGCMDriver::GetLastTokenFetchTime() {
+  return last_token_fetch_time_;
+}
+
+void CustomFakeGCMDriver::SetLastTokenFetchTime(const base::Time& time) {
+  last_token_fetch_time_ = time;
+}
+
 }  // namespace
 
 class GCMAccountTrackerTest : public testing::Test {
@@ -165,6 +175,11 @@ class GCMAccountTrackerTest : public testing::Test {
   GCMAccountTracker* tracker() { return tracker_.get(); }
   CustomFakeGCMDriver* driver() { return &driver_; }
 
+  // Accessors to private methods of account tracker.
+  bool IsFetchingRequired() const;
+  bool IsTokenReportingRequired() const;
+  base::TimeDelta GetTimeToNextTokenReporting() const;
+
  private:
   CustomFakeGCMDriver driver_;
 
@@ -237,6 +252,18 @@ void GCMAccountTrackerTest::IssueError(const std::string& account_key) {
       GoogleServiceAuthError(GoogleServiceAuthError::SERVICE_UNAVAILABLE));
 }
 
+bool GCMAccountTrackerTest::IsFetchingRequired() const {
+  return tracker_->IsTokenFetchingRequired();
+}
+
+bool GCMAccountTrackerTest::IsTokenReportingRequired() const {
+  return tracker_->IsTokenReportingRequired();
+}
+
+base::TimeDelta GCMAccountTrackerTest::GetTimeToNextTokenReporting() const {
+  return tracker_->GetTimeToNextTokenReporting();
+}
+
 TEST_F(GCMAccountTrackerTest, NoAccounts) {
   EXPECT_FALSE(driver()->update_accounts_called());
   tracker()->Start();
@@ -403,7 +430,7 @@ TEST_F(GCMAccountTrackerTest, PostponeTokenFetchingUntilConnected) {
   EXPECT_EQ(1UL, tracker()->get_pending_token_request_count());
 }
 
-TEST_F(GCMAccountTrackerTest, IvalidateExpiredTokens) {
+TEST_F(GCMAccountTrackerTest, InvalidateExpiredTokens) {
   StartAccountSignIn(kAccountId1);
   StartAccountSignIn(kAccountId2);
   tracker()->Start();
@@ -421,6 +448,63 @@ TEST_F(GCMAccountTrackerTest, IvalidateExpiredTokens) {
   EXPECT_EQ(1UL, tracker()->get_pending_token_request_count());
 }
 
+// Testing for whether there are still more tokens to be fetched. Typically the
+// need for token fetching triggers immediate request, unless there is no
+// connection, that is why connection is set on and off in this test.
+TEST_F(GCMAccountTrackerTest, IsTokenFetchingRequired) {
+  tracker()->Start();
+  driver()->SetConnected(false);
+  EXPECT_FALSE(IsFetchingRequired());
+  StartAccountSignIn(kAccountId1);
+  FinishAccountSignIn(kAccountId1);
+  EXPECT_TRUE(IsFetchingRequired());
+
+  driver()->SetConnected(true);
+  EXPECT_FALSE(IsFetchingRequired());  // Indicates that fetching has started.
+  IssueAccessToken(kAccountId1);
+  EXPECT_FALSE(IsFetchingRequired());
+
+  driver()->SetConnected(false);
+  StartAccountSignIn(kAccountId2);
+  FinishAccountSignIn(kAccountId2);
+  EXPECT_TRUE(IsFetchingRequired());
+
+  IssueExpiredAccessToken(kAccountId2);
+  // Make sure that if the token was expired it is still needed.
+  EXPECT_TRUE(IsFetchingRequired());
+}
+
+// Tests what is the expected time to the next token fetching.
+TEST_F(GCMAccountTrackerTest, GetTimeToNextTokenReporting) {
+  tracker()->Start();
+  // At this point the last token fetch time is never.
+  EXPECT_EQ(base::TimeDelta(), GetTimeToNextTokenReporting());
+
+  driver()->SetLastTokenFetchTime(base::Time::Now());
+  EXPECT_TRUE(GetTimeToNextTokenReporting() <=
+                  base::TimeDelta::FromSeconds(12 * 60 * 60));
+}
+
+// Tests conditions when token reporting is required.
+TEST_F(GCMAccountTrackerTest, IsTokenReportingRequired) {
+  tracker()->Start();
+  // Required because it is overdue.
+  EXPECT_TRUE(IsTokenReportingRequired());
+
+  // Not required because it just happened.
+  driver()->SetLastTokenFetchTime(base::Time::Now());
+  EXPECT_FALSE(IsTokenReportingRequired());
+
+  SignInAccount(kAccountId1);
+  IssueAccessToken(kAccountId1);
+  driver()->ResetResults();
+  // Reporting was triggered, which means testing for required will give false,
+  // but we have the update call.
+  SignOutAccount(kAccountId1);
+  EXPECT_TRUE(driver()->update_accounts_called());
+  EXPECT_FALSE(IsTokenReportingRequired());
+}
+
 // TODO(fgorski): Add test for adding account after removal >> make sure it does
 // not mark removal.