[Hashed logging] Add some more tests.

Bug: 951287
Change-Id: I4b4a9ff809908b7804e1111b07d41279d8e66039
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1640797Reviewed-by: Charles . <charleszhao@chromium.org>
Commit-Queue: Tony Yeoman <tby@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669562}

chrome/browser/ui/app_list/search/search_result_ranker/app_list_launch_metrics_provider_unittest.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/app_list/search/search_result_ranker/app_list_launch_metrics_provider.h"
 
+#include <set>
 #include <string>
 
 #include "base/base64.h"
@@ -141,6 +142,22 @@ class AppListLaunchMetricsProviderTest : public testing::Test {
     return proto->secret();
   }
 
+  uint64_t ReadUserId() {
+    std::string proto_str;
+    {
+      base::ScopedBlockingCall scoped_blocking_call(
+          FROM_HERE, base::BlockingType::MAY_BLOCK);
+
+      base::FilePath path = temp_dir_.GetPath().AppendASCII(
+          AppListLaunchMetricsProvider::kStateProtoFilename);
+      CHECK(base::ReadFileToString(path, &proto_str));
+    }
+
+    auto proto = std::make_unique<AppListLaunchRecorderStateProto>();
+    CHECK(proto->ParseFromString(proto_str));
+    return proto->recurrence_ranker_user_id();
+  }
+
   void WriteStateProto(const std::string& secret) {
     AppListLaunchRecorderStateProto proto;
     proto.set_recurrence_ranker_user_id(kUserId);
@@ -160,6 +177,12 @@ class AppListLaunchMetricsProviderTest : public testing::Test {
     Wait();
   }
 
+  void DeleteStateProto() {
+    DeleteFile(temp_dir_.GetPath().AppendASCII(
+                   AppListLaunchMetricsProvider::kStateProtoFilename),
+               false);
+  }
+
   void AddLog(
       const std::string& target,
       const std::string& query,
@@ -225,6 +248,17 @@ TEST_F(AppListLaunchMetricsProviderTest, SucceedsLoadingExistingSecret) {
   ExpectNoErrors();
 }
 
+TEST_F(AppListLaunchMetricsProviderTest, DisableOnInvalidSecret) {
+  WriteStateProto("wrong length");
+
+  MakeProvider();
+  InitProvider();
+
+  ExpectDisabled();
+  histogram_tester_.ExpectUniqueSample("Apps.AppListLaunchRecorderError",
+                                       MetricsProviderError::kInvalidSecret, 1);
+}
+
 // Tests that a call to ProvideCurrentSessionData populates protos for each log,
 // and that those protos contain the right values.
 TEST_F(AppListLaunchMetricsProviderTest, CorrectHashedValues) {
@@ -326,4 +360,24 @@ TEST_F(AppListLaunchMetricsProviderTest,
   ExpectNoErrors();
 }
 
+// Without an existing saved state, instantiating a metrics provider should save
+// an almost certainly unique user ID and secret. Test this by creating a few
+// blank-slate metrics providers.
+TEST_F(AppListLaunchMetricsProviderTest, UserIDsAndSecretsAreUnique) {
+  const int num_runs = 10;
+
+  std::set<uint64_t> user_ids;
+  std::set<std::string> secrets;
+  for (int i = 0; i < num_runs; ++i) {
+    DeleteStateProto();
+    MakeProvider();
+    InitProvider();
+    secrets.insert(ReadSecret());
+    user_ids.insert(ReadUserId());
+  }
+
+  EXPECT_EQ(static_cast<size_t>(num_runs), secrets.size());
+  EXPECT_EQ(static_cast<size_t>(num_runs), user_ids.size());
+}
+
 }  // namespace app_list