shill: wifi: Disable or reduce frequency of background scan.

For details, see corresponding flimflam patch:

https://gerrit.chromium.org/gerrit/#change,24960

Also, rename per style and fix a bug in NumEndpoints (returning bool
rather than an int) and add more unit tests.

BUG=chromium-os:31715
TEST=unit tests

Change-Id: I9b0c6f1abc660a44a43f34b1dec2230c6cf6cfde
Reviewed-on: https://gerrit.chromium.org/gerrit/25376
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
diff --git a/wifi_service_unittest.cc b/wifi_service_unittest.cc
index fe92191..c06caa0 100644
--- a/wifi_service_unittest.cc
+++ b/wifi_service_unittest.cc
@@ -992,6 +992,7 @@
   EXPECT_CALL(adaptor, EmitUint8Changed(
       flimflam::kSignalStrengthProperty, kOkEndpointStrength));
   service->AddEndpoint(ok_endpoint);
+  EXPECT_EQ(1, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Endpoint with stronger signal updates values.
@@ -1002,6 +1003,7 @@
   EXPECT_CALL(adaptor, EmitUint8Changed(
       flimflam::kSignalStrengthProperty, kGoodEndpointStrength));
   service->AddEndpoint(good_endpoint);
+  EXPECT_EQ(2, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Endpoint with lower signal does not change values.
@@ -1010,6 +1012,7 @@
   EXPECT_CALL(adaptor,
               EmitUint8Changed(flimflam::kSignalStrengthProperty, _)).Times(0);
   service->AddEndpoint(bad_endpoint);
+  EXPECT_EQ(3, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Removing non-optimal endpoint does not change values.
@@ -1018,6 +1021,7 @@
   EXPECT_CALL(adaptor,
               EmitUint8Changed(flimflam::kSignalStrengthProperty, _)).Times(0);
   service->RemoveEndpoint(bad_endpoint);
+  EXPECT_EQ(2, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Removing optimal endpoint updates values.
@@ -1028,6 +1032,7 @@
   EXPECT_CALL(adaptor, EmitUint8Changed(
       flimflam::kSignalStrengthProperty, kOkEndpointStrength));
   service->RemoveEndpoint(good_endpoint);
+  EXPECT_EQ(1, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Removing last endpoint updates values (and doesn't crash).
@@ -1035,6 +1040,7 @@
   EXPECT_CALL(adaptor, EmitStringChanged(flimflam::kWifiBSsid, _));
   EXPECT_CALL(adaptor, EmitUint8Changed(flimflam::kSignalStrengthProperty, _));
   service->RemoveEndpoint(ok_endpoint);
+  EXPECT_EQ(0, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 }
 
@@ -1045,6 +1051,7 @@
   EXPECT_CALL(adaptor, EmitBoolChanged(_, _)).Times(AnyNumber());
   service->AddEndpoint(bad_endpoint);
   service->AddEndpoint(ok_endpoint);
+  EXPECT_EQ(2, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Setting current endpoint forces adoption of its values, even if it
@@ -1064,6 +1071,7 @@
   EXPECT_CALL(adaptor,
               EmitUint8Changed(flimflam::kSignalStrengthProperty, _)).Times(0);
   service->AddEndpoint(good_endpoint);
+  EXPECT_EQ(3, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Removing a better endpoint doesn't matter, when current endpoint is set.
@@ -1101,6 +1109,7 @@
   EXPECT_CALL(adaptor, EmitBoolChanged(_, _)).Times(AnyNumber());
   service->AddEndpoint(ok_endpoint);
   service->AddEndpoint(good_endpoint);
+  EXPECT_EQ(2, service->GetEndpointCount());
   Mock::VerifyAndClearExpectations(&adaptor);
 
   // Updating sub-optimal Endpoint doesn't update Service.