sync: add InternalComponentsFactory::Switches to simplify passing switches to internal components.

sync/engine/sync_scheduler_impl.h

Index: sync/engine/sync_scheduler_impl.h
diff --git a/sync/engine/sync_scheduler_impl.h b/sync/engine/sync_scheduler_impl.h
index 586ccdc363822f6d121e4334e945760c0b9df326..e5f3acf61d27aef8463e987beab557e914f059fc 100644
--- a/sync/engine/sync_scheduler_impl.h
+++ b/sync/engine/sync_scheduler_impl.h
@@ -28,12 +28,16 @@
 
 namespace syncer {
 
+class BackoffDelayProvider;
+
 class SyncSchedulerImpl : public SyncScheduler {
  public:
   // |name| is a display string to identify the syncer thread.  Takes
-  // |ownership of |syncer|.
+  // |ownership of |syncer| and |delay_provider|.
   SyncSchedulerImpl(const std::string& name,
-                    sessions::SyncSessionContext* context, Syncer* syncer);
+                    BackoffDelayProvider* delay_provider,
+                    sessions::SyncSessionContext* context,
+                    Syncer* syncer);
 
   // Calls Stop().
   virtual ~SyncSchedulerImpl();
@@ -72,16 +76,6 @@ class SyncSchedulerImpl : public SyncScheduler {
   virtual void OnSyncProtocolError(
       const sessions::SyncSessionSnapshot& snapshot) OVERRIDE;
 
-  // DDOS avoidance function.  Calculates how long we should wait before trying
-  // again after a failed sync attempt, where the last delay was |base_delay|.
-  // TODO(tim): Look at URLRequestThrottlerEntryInterface.
-  static base::TimeDelta GetRecommendedDelay(const base::TimeDelta& base_delay);
-
-  // For integration tests only.  Override initial backoff value.
-  // TODO(tim): Remove this, use command line flag and plumb through. Done
-  // this way to reduce diffs in hotfix.
-  static void ForceShortInitialBackoffRetry();
-
  private:
   enum JobProcessDecision {
     // Indicates we should continue with the current job.
@@ -150,17 +144,6 @@ class SyncSchedulerImpl : public SyncScheduler {
   FRIEND_TEST_ALL_PREFIXES(SyncSchedulerTest, TransientPollFailure);
   FRIEND_TEST_ALL_PREFIXES(SyncSchedulerTest, GetInitialBackoffDelay);
 
-  // A component used to get time delays associated with exponential backoff.
-  // Encapsulated into a class to facilitate testing.
-  class DelayProvider {
-   public:
-    DelayProvider();
-    virtual base::TimeDelta GetDelay(const base::TimeDelta& last_delay);
-    virtual ~DelayProvider();
-   private:
-    DISALLOW_COPY_AND_ASSIGN(DelayProvider);
-  };
-
   struct WaitInterval {
     enum Mode {
       // Uninitialized state, should not be set in practice.
@@ -234,11 +217,6 @@ class SyncSchedulerImpl : public SyncScheduler {
   // Helper to ScheduleNextSync in case of consecutive sync errors.
   void HandleContinuationError(const SyncSessionJob& old_job);
 
-  // Helper to calculate the initial value for exponential backoff.
-  // See possible values and comments in polling_constants.h.
-  base::TimeDelta GetInitialBackoffDelay(
-      const sessions::ModelNeutralState& state) const;
-
   // Determines if it is legal to run |job| by checking current
   // operational mode, backoff or throttling, freshness
   // (so we don't make redundant syncs), and connection.
@@ -348,7 +326,7 @@ class SyncSchedulerImpl : public SyncScheduler {
   // Current wait state.  Null if we're not in backoff and not throttled.
   scoped_ptr<WaitInterval> wait_interval_;
 
-  scoped_ptr<DelayProvider> delay_provider_;
+  scoped_ptr<BackoffDelayProvider> delay_provider_;
 
   // Invoked to run through the sync cycle.
   scoped_ptr<Syncer> syncer_;