[Policy] HostContentSettingsMap: Add AreUserExceptionsAllowedForType() and tests.

components/content_settings/core/browser/host_content_settings_map.cc

Index: components/content_settings/core/browser/host_content_settings_map.cc
diff --git a/components/content_settings/core/browser/host_content_settings_map.cc b/components/content_settings/core/browser/host_content_settings_map.cc
index 5307adea4accab3db64c9445ad8e715bf5ec0bed..75cb827337388e1acec917a1b0542f8a4e4c111f 100644
--- a/components/content_settings/core/browser/host_content_settings_map.cc
+++ b/components/content_settings/core/browser/host_content_settings_map.cc
@@ -147,20 +147,21 @@ HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
       prefs_(prefs),
       is_off_the_record_(is_incognito_profile || is_guest_profile) {
   DCHECK(!(is_incognito_profile && is_guest_profile));
-  content_settings::ObservableProvider* policy_provider =
-      new content_settings::PolicyProvider(prefs_);
-  policy_provider->AddObserver(this);
-  content_settings_providers_[POLICY_PROVIDER] = policy_provider;
-
-  content_settings::PrefProvider* pref_provider =
-      new content_settings::PrefProvider(prefs_, is_off_the_record_);
-  pref_provider->AddObserver(this);
-  content_settings_providers_[PREF_PROVIDER] = pref_provider;
+  content_settings_providers_[POLICY_PROVIDER] =
+      policy_provider_ =
+          new content_settings::PolicyProvider(prefs_);
+  policy_provider_->AddObserver(this);
+
+  content_settings_providers_[PREF_PROVIDER] =
+      pref_provider_ =
+          new content_settings::PrefProvider(prefs_, is_off_the_record_);
+  pref_provider_->AddObserver(this);
+
   // This ensures that content settings are cleared for the guest profile. This
   // wouldn't be needed except that we used to allow settings to be stored for
   // the guest profile and so we need to ensure those get cleared.
   if (is_guest_profile)
-    pref_provider->ClearPrefs();
+    pref_provider_->ClearPrefs();
 
   content_settings::ObservableProvider* default_provider =
       new content_settings::DefaultProvider(prefs_, is_off_the_record_);
@@ -219,9 +220,10 @@ ContentSetting HostContentSettingsMap::GetDefaultContentSettingFromProvider(
   return CONTENT_SETTING_DEFAULT;
 }
 
-ContentSetting HostContentSettingsMap::GetDefaultContentSetting(
-    ContentSettingsType content_type,
-    std::string* provider_id) const {
+HostContentSettingsMap::ContentSettingWithProviderType
+HostContentSettingsMap::GetDefaultContentSetting(
+    ContentSettingsType content_type) const {
+  ContentSettingWithProviderType ret;  // Initialized.
   UsedContentSettingsProviders();
 
   // Iterate through the list of providers and return the first non-NULL value
@@ -241,13 +243,34 @@ ContentSetting HostContentSettingsMap::GetDefaultContentSetting(
               .get());
     }
     if (default_setting != CONTENT_SETTING_DEFAULT) {
-      if (provider_id)
-        *provider_id = kProviderNamesSourceMap[provider->first].provider_name;
-      return default_setting;
+      ret.content_setting = default_setting;
+      ret.provider_type = provider->first;
+      break;
     }
   }
 
-  return CONTENT_SETTING_DEFAULT;
+  return ret;
+}
+
+// FIXME(huangs): Remove this and fix callers.
+ContentSetting HostContentSettingsMap::GetDefaultContentSetting(
+    ContentSettingsType content_type,
+    std::string* provider_name) const {
+  ContentSettingWithProviderType result =
+      GetDefaultContentSetting(content_type);
+  if (result.provider_type != NUM_PROVIDER_TYPES && provider_name) {
+    *provider_name = kProviderNamesSourceMap[
+        result.provider_type].provider_name;
+  }
+  return result.content_setting;
+}
+
+bool HostContentSettingsMap::AreUserExceptionsAllowedForType(

[raymes, 2016/04/12 04:52:47]

I'm guessing this function is going to become more complicated later? (Similar
to in the other CL?)

[huangs, 2016/04/12 14:19:13]

Yes.  The advantage of adding this function now is that we can immediately
proceed on the JS work.

+    ContentSettingsType content_type) const {
+  // Disable if default setting came from policy provider.
+  ProviderType default_settings_provider =
+      GetDefaultContentSetting(content_type).provider_type;
+  return default_settings_provider != POLICY_PROVIDER;
 }
 
 ContentSetting HostContentSettingsMap::GetContentSetting(
@@ -520,7 +543,7 @@ void HostContentSettingsMap::UpdateLastUsageByPattern(
     ContentSettingsType content_type) {
   UsedContentSettingsProviders();
 
-  GetPrefProvider()->UpdateLastUsage(
+  pref_provider_->UpdateLastUsage(
       primary_pattern, secondary_pattern, content_type);
 }
 
@@ -540,7 +563,7 @@ base::Time HostContentSettingsMap::GetLastUsageByPattern(
     ContentSettingsType content_type) {
   UsedContentSettingsProviders();
 
-  return GetPrefProvider()->GetLastUsage(
+  return pref_provider_->GetLastUsage(
       primary_pattern, secondary_pattern, content_type);
 }
 
@@ -561,7 +584,7 @@ void HostContentSettingsMap::SetPrefClockForTesting(
     scoped_ptr<base::Clock> clock) {
   UsedContentSettingsProviders();
 
-  GetPrefProvider()->SetClockForTesting(std::move(clock));
+  pref_provider_->SetClockForTesting(std::move(clock));
 }
 
 void HostContentSettingsMap::ClearSettingsForOneType(
@@ -727,8 +750,7 @@ HostContentSettingsMap::GetProviderTypeFromSource(const std::string& source) {
 }
 
 content_settings::PrefProvider* HostContentSettingsMap::GetPrefProvider() {
-  return static_cast<content_settings::PrefProvider*>(
-      content_settings_providers_[PREF_PROVIDER]);
+  return pref_provider_;
 }
 
 scoped_ptr<base::Value> HostContentSettingsMap::GetWebsiteSettingInternal(