Activate DelayUnsafeAds only if AdTagging enabled

The DelayUnsafeAds field trial parameters should only be queried if the client has
AdTagging enabled.

Bug: 856271
Change-Id: Ie4c19bb735c8b20c2454da21f12c3c7ce7cd4e02
Reviewed-on: https://chromium-review.googlesource.com/1117326Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Commit-Queue: John Delaney <johnidel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571094}

components/subresource_filter/content/common/ad_delay_throttle.cc

@@ -109,18 +109,20 @@ base::TimeDelta AdDelayThrottle::DeferCondition::OnReadyToDefer() {
 constexpr base::TimeDelta AdDelayThrottle::kDefaultDelay;
 
 AdDelayThrottle::Factory::Factory()
-    : insecure_delay_(base::TimeDelta::FromMilliseconds(
-          base::GetFieldTrialParamByFeatureAsInt(
-              kDelayUnsafeAds,
-              kInsecureDelayParam,
-              kDefaultDelay.InMilliseconds()))),
+    : delay_enabled_(base::FeatureList::IsEnabled(kAdTagging) &&
+                     base::FeatureList::IsEnabled(kDelayUnsafeAds)),
+      insecure_delay_(base::TimeDelta::FromMilliseconds(
+          delay_enabled_ ? base::GetFieldTrialParamByFeatureAsInt(
+                               kDelayUnsafeAds,
+                               kInsecureDelayParam,
+                               kDefaultDelay.InMilliseconds())
+                         : 0)),
       non_isolated_delay_(base::TimeDelta::FromMilliseconds(
-          base::GetFieldTrialParamByFeatureAsInt(
-              kDelayUnsafeAds,
-              kNonIsolatedDelayParam,
-              kDefaultDelay.InMilliseconds()))),
-      delay_enabled_(base::FeatureList::IsEnabled(kAdTagging) &&
-                     base::FeatureList::IsEnabled(kDelayUnsafeAds)) {}
+          delay_enabled_ ? base::GetFieldTrialParamByFeatureAsInt(
+                               kDelayUnsafeAds,
+                               kNonIsolatedDelayParam,
+                               kDefaultDelay.InMilliseconds())
+                         : 0)) {}
 
 AdDelayThrottle::Factory::~Factory() = default;
 

components/subresource_filter/content/common/ad_delay_throttle.h

@@ -56,9 +56,9 @@ class AdDelayThrottle : public content::URLLoaderThrottle {
     bool delay_enabled() const { return delay_enabled_; }
 
    private:
+    const bool delay_enabled_ = false;
     const base::TimeDelta insecure_delay_;
     const base::TimeDelta non_isolated_delay_;
-    const bool delay_enabled_ = false;
 
     DISALLOW_COPY_AND_ASSIGN(Factory);
   };

components/subresource_filter/content/common/ad_delay_throttle_unittest.cc

@@ -141,6 +141,10 @@ TEST_F(AdDelayThrottleTest, NoFeature_NoDelay) {
 TEST_F(AdDelayThrottleTest, NoAdTagging_NoDelay) {
   base::test::ScopedFeatureList scoped_disable;
   scoped_disable.InitAndDisableFeature(kAdTagging);
+  base::test::ScopedFeatureList scoped_params;
+  scoped_params.InitAndEnableFeatureWithParameters(
+      kDelayUnsafeAds,
+      {{kInsecureDelayParam, "50"}, {kNonIsolatedDelayParam, "100"}});
 
   AdDelayThrottle::Factory factory;
   auto throttle = factory.MaybeCreate(std::make_unique<MockMetadataProvider>());
@@ -152,6 +156,8 @@ TEST_F(AdDelayThrottleTest, NoAdTagging_NoDelay) {
   scoped_environment_.RunUntilIdle();
 
   EXPECT_TRUE(client_->has_received_completion());
+  EXPECT_FALSE(base::FieldTrialList::IsTrialActive(
+      base::FeatureList::GetFieldTrial(kDelayUnsafeAds)->trial_name()));
 }
 
 TEST_F(AdDelayThrottleTest, AdDelay) {