Cancel prerendering when a request is paused or removed.

components/offline_pages/background/request_coordinator_unittest.cc

Index: components/offline_pages/background/request_coordinator_unittest.cc
diff --git a/components/offline_pages/background/request_coordinator_unittest.cc b/components/offline_pages/background/request_coordinator_unittest.cc
index 41393a47f6dd97cef81d1234cae0b53e2d9501b4..cdb7ef7b119f271cddd2a200718300135a910fdf 100644
--- a/components/offline_pages/background/request_coordinator_unittest.cc
+++ b/components/offline_pages/background/request_coordinator_unittest.cc
@@ -606,6 +606,50 @@ TEST_F(RequestCoordinatorTest, StartProcessingThenStopProcessingLater) {
   EXPECT_TRUE(OfflinerWasCanceled());
 }
 
+// This tests that canceling a request will result in TryNextRequest() getting
+// called.
+TEST_F(RequestCoordinatorTest, RemoveInflightRequest) {
+  // Add a request to the queue, wait for callbacks to finish.
+  offline_pages::SavePageRequest request1(kRequestId1, kUrl1, kClientId1,
+                                          base::Time::Now(), kUserRequested);
+  coordinator()->queue()->AddRequest(
+      request1, base::Bind(&RequestCoordinatorTest::AddRequestDone,
+                           base::Unretained(this)));
+  PumpLoop();
+
+  // Ensure the start processing request stops before the completion callback.
+  EnableOfflinerCallback(false);
+
+  DeviceConditions device_conditions(false, 75,
+                                     net::NetworkChangeNotifier::CONNECTION_3G);
+  base::Callback<void(bool)> callback = base::Bind(
+      &RequestCoordinatorTest::EmptyCallbackFunction, base::Unretained(this));
+  EXPECT_TRUE(coordinator()->StartProcessing(device_conditions, callback));
+
+  // Let all the async parts of the start processing pipeline run to completion.
+  PumpLoop();
+
+  // Remove the request while it is processing.
+  std::vector<int64_t> request_ids{kRequestId1};
+  coordinator()->RemoveRequests(request_ids);
+
+  // Let the async callbacks in the cancel run.
+  PumpLoop();
+
+  // Simulate the offliner responding to the cancel request
+  SendOfflinerDoneCallback(request1,

[dougarnett, 2016/08/23 20:59:45]

as discussed, we may seeing that SendToOffliner was never called - which is a
clue maybe to do another PumpLoop before the Remove if we want to exercise the
path where it is called

+                           Offliner::RequestStatus::PRERENDERING_CANCELED);
+  PumpLoop();
+
+  // OfflinerDoneCallback will not end up getting called with status SAVED,
+  // since we cancelled the event before the LoadAndSave completed.
+  EXPECT_EQ(Offliner::RequestStatus::PRERENDERING_CANCELED,
+            last_offlining_status());
+
+  // Since offliner was started, it will have seen cancel call.
+  EXPECT_TRUE(OfflinerWasCanceled());
+}
+
 TEST_F(RequestCoordinatorTest, WatchdogTimeout) {
   // Build a request to use with the pre-renderer, and put it on the queue.
   offline_pages::SavePageRequest request(