Introduce activation scope logic.

components/subresource_filter/core/browser/subresource_filter_features.cc

Index: components/subresource_filter/core/browser/subresource_filter_features.cc
diff --git a/components/subresource_filter/core/browser/subresource_filter_features.cc b/components/subresource_filter/core/browser/subresource_filter_features.cc
index 3e16a9f98d7aed7b2f8538c298fca6744e0ea7fa..a0dea3959a6db787c5a27ba211922ebcacfe608a 100644
--- a/components/subresource_filter/core/browser/subresource_filter_features.cc
+++ b/components/subresource_filter/core/browser/subresource_filter_features.cc
@@ -19,6 +19,11 @@ const char kActivationStateDryRun[] = "dryrun";
 const char kActivationStateEnabled[] = "enabled";
 const char kActivationStateDisabled[] = "disabled";
 
+const char kActivationScopeParameterName[] = "activation_scope";
+const char kActivationScopeAllSites[] = "all_sites";
+const char kActivationScopeActivationList[] = "activation_list";
+const char kActivationScopeNoSites[] = "no_sites";
+
 ActivationState GetMaximumActivationState() {
   std::string activation_state = variations::GetVariationParamValueByFeature(
       kSafeBrowsingSubresourceFilter, kActivationStateParameterName);
@@ -29,4 +34,15 @@ ActivationState GetMaximumActivationState() {
   return ActivationState::DISABLED;
 }
 
+ActivationScope GetCurrentActivationScope() {
+  std::string activation_scope = variations::GetVariationParamValueByFeature(
+      kSafeBrowsingSubresourceFilter, kActivationScopeParameterName);
+  if (base::LowerCaseEqualsASCII(activation_scope, kActivationScopeAllSites))
+    return ActivationScope::ALL_SITES;
+  else if (base::LowerCaseEqualsASCII(activation_scope,
+                                      kActivationScopeActivationList))
+    return ActivationScope::ACTIVATION_LIST;
+  return ActivationScope::NO_SITES;
+}
+
 }  // namespace subresource_filter