sync: Handle POLL jobs in separate a code path

sync/engine/sync_scheduler_whitebox_unittest.cc

Index: sync/engine/sync_scheduler_whitebox_unittest.cc
diff --git a/sync/engine/sync_scheduler_whitebox_unittest.cc b/sync/engine/sync_scheduler_whitebox_unittest.cc
index 01adb85ee79235a2e179980e6fef2fdf583cd63f..77bb11dd40bc6e85395b392981fdb2a282d9a911 100644
--- a/sync/engine/sync_scheduler_whitebox_unittest.cc
+++ b/sync/engine/sync_scheduler_whitebox_unittest.cc
@@ -111,6 +111,10 @@ class SyncSchedulerWhiteboxTest : public testing::Test {
     return DecideOnJob(job, SyncSchedulerImpl::NORMAL_PRIORITY);
   }
 
+  bool ShouldPoll() {
+    return scheduler_->ShouldPoll();
+  }
+
   SyncSessionContext* context() { return context_.get(); }
 
  private:
@@ -174,23 +178,27 @@ TEST_F(SyncSchedulerWhiteboxTest, ContinueNudge) {
   EXPECT_EQ(decision, SyncSchedulerImpl::CONTINUE);
 }
 
-TEST_F(SyncSchedulerWhiteboxTest, DropPoll) {
+TEST_F(SyncSchedulerWhiteboxTest, ContinuePoll) {
   InitializeSyncerOnNormalMode();
-  SetMode(SyncScheduler::CONFIGURATION_MODE);
-
-  SyncSchedulerImpl::JobProcessDecision decision = CreateAndDecideJob(
-      SyncSessionJob::POLL);
-
-  EXPECT_EQ(decision, SyncSchedulerImpl::DROP);
+  EXPECT_TRUE(ShouldPoll());
 }
 
-TEST_F(SyncSchedulerWhiteboxTest, ContinuePoll) {
+TEST_F(SyncSchedulerWhiteboxTest, DropPollInConfigureMode) {
   InitializeSyncerOnNormalMode();
+  SetMode(SyncScheduler::CONFIGURATION_MODE);
+  EXPECT_FALSE(ShouldPoll());
+}
 
-  SyncSchedulerImpl::JobProcessDecision decision = CreateAndDecideJob(
-      SyncSessionJob::POLL);
+TEST_F(SyncSchedulerWhiteboxTest, DropPollWhenThrottled) {
+  InitializeSyncerOnNormalMode();
+  SetWaitIntervalToThrottled();
+  EXPECT_FALSE(ShouldPoll());
+}
 
-  EXPECT_EQ(decision, SyncSchedulerImpl::CONTINUE);
+TEST_F(SyncSchedulerWhiteboxTest, DropPollInBackoff) {
+  InitializeSyncerOnNormalMode();
+  SetWaitIntervalToExponentialBackoff();
+  EXPECT_FALSE(ShouldPoll());
 }
 
 TEST_F(SyncSchedulerWhiteboxTest, ContinueConfiguration) {