Quota: Remove RunUntilIdle() usage from QuotaSettingsTest.

This CL replaces calls to base::TaskEnvironment::RunUntilIdle() with a
base::RunLoop that is Quit() when the tested function's base::Callback
is executed. A few minor cleanups are included.

Change-Id: I94488c922df13fe67bdd246c80c7f15064a1bda8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2644144
Commit-Queue: Jarryd Goodman <jarrydg@chromium.org>
Reviewed-by: Jarryd Goodman <jarrydg@chromium.org>
Auto-Submit: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846287}

storage/browser/quota/quota_settings_unittest.cc

@@ -8,6 +8,8 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/scoped_temp_dir.h"
+#include "base/optional.h"
+#include "base/run_loop.h"
 #include "base/test/bind.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/task_environment.h"
@@ -39,15 +41,28 @@ class QuotaSettingsTest : public testing::Test {
   QuotaSettingsTest() = default;
   void SetUp() override { ASSERT_TRUE(data_dir_.CreateUniqueTempDir()); }
 
- protected:
-  base::test::ScopedFeatureList scoped_feature_list_;
-  base::test::TaskEnvironment task_environment_;
+  // Synchronous proxy to GetNominalDynamicSettings().
+  base::Optional<QuotaSettings> GetSettings(
+      bool is_incognito,
+      QuotaDeviceInfoHelper* device_info_helper) {
+    base::Optional<QuotaSettings> quota_settings;
+    base::RunLoop run_loop;
+    GetNominalDynamicSettings(
+        profile_path(), is_incognito, device_info_helper,
+        base::BindLambdaForTesting([&](base::Optional<QuotaSettings> settings) {
+          quota_settings = std::move(settings);
+          run_loop.Quit();
+        }));
+    run_loop.Run();
+    return quota_settings;
+  }
+
   const base::FilePath& profile_path() const { return data_dir_.GetPath(); }
 
- private:
+ protected:
+  base::test::ScopedFeatureList scoped_feature_list_;
   base::ScopedTempDir data_dir_;
-  QuotaSettings quota_settings_;
-  DISALLOW_COPY_AND_ASSIGN(QuotaSettingsTest);
+  base::test::TaskEnvironment task_environment_;
 };
 
 class QuotaSettingsIncognitoTest : public QuotaSettingsTest {
@@ -64,24 +79,15 @@ class QuotaSettingsIncognitoTest : public QuotaSettingsTest {
   }
 
   void GetAndTestSettings(const int64_t physical_memory_amount) {
-    bool callback_executed = false;
-    GetNominalDynamicSettings(
-        profile_path(), true, device_info_helper(),
-        base::BindLambdaForTesting([&](base::Optional<QuotaSettings> settings) {
-          callback_executed = true;
-          EXPECT_LE(physical_memory_amount *
-                        GetIncognitoQuotaRatioLowerBound_ForTesting(),
+    base::Optional<QuotaSettings> settings =
+        GetSettings(true, &device_info_helper_);
+    ASSERT_TRUE(settings.has_value());
+    EXPECT_LE(
+        physical_memory_amount * GetIncognitoQuotaRatioLowerBound_ForTesting(),
         settings->pool_size);
-          EXPECT_GE(physical_memory_amount *
-                        GetIncognitoQuotaRatioUpperBound_ForTesting(),
+    EXPECT_GE(
+        physical_memory_amount * GetIncognitoQuotaRatioUpperBound_ForTesting(),
         settings->pool_size);
-        }));
-    task_environment_.RunUntilIdle();
-    EXPECT_TRUE(callback_executed);
-  }
-
-  MockQuotaDeviceInfoHelper* device_info_helper() {
-    return &device_info_helper_;
   }
 
  private:
@@ -93,19 +99,13 @@ TEST_F(QuotaSettingsTest, Default) {
   ON_CALL(device_info_helper, AmountOfTotalDiskSpace(_))
       .WillByDefault(::testing::Return(2000));
 
-  bool callback_executed = false;
-  GetNominalDynamicSettings(
-      profile_path(), false, &device_info_helper,
-      base::BindLambdaForTesting([&](base::Optional<QuotaSettings> settings) {
-        callback_executed = true;
-        ASSERT_NE(settings, base::nullopt);
+  base::Optional<QuotaSettings> settings =
+      GetSettings(false, &device_info_helper);
+  ASSERT_TRUE(settings.has_value());
   // 1600 = 2000 * default PoolSizeRatio (0.8)
   EXPECT_EQ(settings->pool_size, 1600);
   // 1200 = 1600 * default PerHostRatio (.75)
   EXPECT_EQ(settings->per_host_quota, 1200);
-      }));
-  task_environment_.RunUntilIdle();
-  EXPECT_TRUE(callback_executed);
 }
 
 TEST_F(QuotaSettingsIncognitoTest, IncognitoDynamicQuota_LowPhysicalMemory) {