cleanup: Clarify DnsLatency problem

Switch kFailedToResolveAllHosts to the clearer kHostResolutionFailure to
denote when one or more hosts failed DNS resolution.

BUG=chromium:956783
TEST=unit_tests --gtest_filter=DnsLatencyRoutineTest.*

Change-Id: I0392df692919a55896e439edc5f53801d756873d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490069Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Kartik Hegde <khegde@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819546}

chrome/browser/chromeos/net/network_diagnostics/README.md

@@ -103,7 +103,7 @@ Problems:
 Tests whether the DNS latency is below an acceptable threshold.
 
 Problems:
-* `kFailedToResolveAllHosts`: Failed to resolve one or more hosts.
+* `kHostResolutionFailure`: Failed to resolve one or more hosts.
 * `kSlightlyAboveThreshold`: Average DNS latency across hosts is slightly above
    expected threshold.
 * `kSignificantlyAboveThreshold`: Average DNS latency across hosts is

chrome/browser/chromeos/net/network_diagnostics/dns_latency_routine.cc

@@ -108,7 +108,7 @@ void DnsLatencyRoutine::AnalyzeResultsAndExecuteCallback() {
   double average_latency = AverageLatency(latencies_);
   if (!successfully_resolved_all_addresses_ || average_latency == 0.0) {
     set_verdict(mojom::RoutineVerdict::kProblem);
-    problems_.emplace_back(mojom::DnsLatencyProblem::kFailedToResolveAllHosts);
+    problems_.emplace_back(mojom::DnsLatencyProblem::kHostResolutionFailure);
   } else if (average_latency > kBadLatencyMs.InMillisecondsF() &&
              average_latency <= kVeryBadLatencyMs.InMillisecondsF()) {
     set_verdict(mojom::RoutineVerdict::kProblem);

chrome/browser/chromeos/net/network_diagnostics/dns_latency_routine_unittest.cc

@@ -233,7 +233,7 @@ TEST_F(DnsLatencyRoutineTest, TestUnsuccessfulResolution) {
   // because a failed resolution attempt already results in a problem.
   SetUpAndRunRoutine(fake_dns_result.get(), kSuccessfulDnsResolutionDelayMs,
                      mojom::RoutineVerdict::kProblem,
-                     {mojom::DnsLatencyProblem::kFailedToResolveAllHosts});
+                     {mojom::DnsLatencyProblem::kHostResolutionFailure});
 }
 
 // This test case represents the scenario where a DNS resolution was successful;

chromeos/services/network_health/public/mojom/network_diagnostics.mojom

@@ -60,9 +60,8 @@ enum DnsResolverPresentProblem {
 // Problems related to the DnsLatencyProblem routine.
 [Extensible]
 enum DnsLatencyProblem {
-  // The routine was unable to successfully resolve all the hosts. Note that
-  // this will be true if one or more hosts could not be successfully resolved.
-  kFailedToResolveAllHosts,
+  // The routine was unable to resolve one or more hosts.
+  kHostResolutionFailure,
   // Average DNS latency across hosts is slightly above expected threshold
   kSlightlyAboveThreshold,
   // Average DNS latency across hosts is significantly above expected threshold