Add migration code to change existing domain scoped content settings to be origin scoped

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 6b56ae6e7f863dec90f9a3cc482015fefa96ccb3..39a971e95ad7f668b314d0b322fc78a2c7518500 100644
--- a/components/content_settings/core/browser/host_content_settings_map.cc
+++ b/components/content_settings/core/browser/host_content_settings_map.cc
@@ -32,6 +32,7 @@
 #include "components/content_settings/core/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
+#include "components/syncable_prefs/pref_model_associator.h"
 #include "net/base/net_errors.h"
 #include "net/base/static_cookie_policy.h"
 #include "url/gurl.h"
@@ -118,11 +119,7 @@ content_settings::PatternPair GetPatternsFromScopingType(
   content_settings::PatternPair patterns;
 
   switch (scoping_type) {
-    case WebsiteSettingsInfo::TOP_LEVEL_DOMAIN_ONLY_SCOPE:
-    case WebsiteSettingsInfo::REQUESTING_DOMAIN_ONLY_SCOPE:
-      patterns.first = ContentSettingsPattern::FromURL(primary_url);
-      patterns.second = ContentSettingsPattern::Wildcard();
-      break;
+    case WebsiteSettingsInfo::TOP_LEVEL_ORIGIN_ONLY_SCOPE:
     case WebsiteSettingsInfo::REQUESTING_ORIGIN_ONLY_SCOPE:
       patterns.first = ContentSettingsPattern::FromURLNoWildcard(primary_url);
       patterns.second = ContentSettingsPattern::Wildcard();
@@ -172,8 +169,12 @@ HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
   content_settings_providers_[DEFAULT_PROVIDER] = default_provider;
 
   MigrateKeygenSettings();
-
+  MigrateDomainScopedSettings();
   RecordNumberOfExceptions();
+
+  syncable_prefs::PrefModelAssociator::SetMergeDataFinishedCallback(
+      base::Bind(&HostContentSettingsMap::MigrateDomainScopedSettings,
+                 base::Unretained(this)));
 }
 
 // static
@@ -497,6 +498,60 @@ void HostContentSettingsMap::MigrateKeygenSettings() {
   }
 }
 
+void HostContentSettingsMap::MigrateDomainScopedSettings() {
+  const ContentSettingsType kDomainScopedTypes[] = {
+    CONTENT_SETTINGS_TYPE_COOKIES,
+#if !defined(OS_ANDROID) && !defined(OS_IOS)

[raymes, 2016/06/16 03:23:51]

Rather than the ifdefs, can we just check to see if
content_settings::ContentSettingsRegistry::GetInstance()->Get returns true?

[lshang, 2016/06/20 01:34:22]

Done.

+    CONTENT_SETTINGS_TYPE_IMAGES,
+    CONTENT_SETTINGS_TYPE_PLUGINS,
+#endif
+#if !defined(OS_IOS)
+    CONTENT_SETTINGS_TYPE_JAVASCRIPT,
+    CONTENT_SETTINGS_TYPE_AUTOMATIC_DOWNLOADS,
+#endif
+    CONTENT_SETTINGS_TYPE_POPUPS
+  };
+  for (const ContentSettingsType& type : kDomainScopedTypes) {
+    DCHECK(content_settings::ContentSettingsRegistry::GetInstance()->Get(type));
+    ContentSettingsForOneType settings;
+    GetSettingsForOneType(type, std::string(), &settings);
+
+    for (const ContentSettingPatternSource& setting_entry : settings) {
+      // Migrate user preference settings only.
+      if (setting_entry.source != "preference")
+        continue;
+      // Migrate ALLOW settings only.
+      if (setting_entry.setting != CONTENT_SETTING_ALLOW)
+        continue;
+      // Skip default settings.
+      if (setting_entry.primary_pattern == ContentSettingsPattern::Wildcard() &&
+          setting_entry.secondary_pattern == ContentSettingsPattern::Wildcard())

[raymes, 2016/06/16 03:23:51]

nit: add {}

[lshang, 2016/06/20 01:34:22]

Done.

+        continue;

[raymes, 2016/06/16 03:23:50]

Should we also DCHECK that the secondary_pattern is a wildcard pattern? 

[lshang, 2016/06/20 01:34:22]

Done.

+      if (setting_entry.primary_pattern.IsGeneratedFromURLDomainScoped()) {

[raymes, 2016/06/16 03:23:50]

What about using "continue" here (if this evaluates to false) to avoid the
indenting below

[lshang, 2016/06/20 01:34:22]

Done.

+        ContentSettingsPattern origin_pattern =
+            ContentSettingsPattern::FromDomainToOrigin(
+                setting_entry.primary_pattern);
+        GURL origin(origin_pattern.ToString());
+        if (origin.is_valid()) {

[raymes, 2016/06/16 03:23:51]

Same here

[lshang, 2016/06/20 01:34:22]

Done.

+          ContentSetting origin_setting =

[raymes, 2016/06/16 03:23:51]

Maybe say:
// Ensure that the current resolved content setting for this origin is allowed.
Otherwise we may be overriding some narrower setting which is set to block.

[lshang, 2016/06/20 01:34:22]

Done.

+              GetContentSetting(origin, origin, type, std::string());
+
+          // Remove the domiain scoped pattern.

[raymes, 2016/06/16 03:23:50]

// Remove the domain scoped pattern. If |origin_setting| is not
CONTENT_SETTING_ALLOW it implies there is some narrower pattern in effect, so
it's still safe to remove the domain-scoped pattern.

[lshang, 2016/06/20 01:34:22]

Done.

+          SetContentSettingCustomScope(setting_entry.primary_pattern,
+                                       setting_entry.secondary_pattern, type,
+                                       std::string(), CONTENT_SETTING_DEFAULT);
+
+          // If the current setting of narrow-down origin is ALLOW, then add a
+          // new setting entry of this origin.

[raymes, 2016/06/16 03:23:51]

// If the current resolved content setting is allowed it's safe to set the
origin-scoped pattern.

[lshang, 2016/06/20 01:34:22]

Done.

+          if (origin_setting == CONTENT_SETTING_ALLOW)
+            SetContentSettingDefaultScope(origin, GURL(), type, std::string(),
+                                          CONTENT_SETTING_ALLOW);
+        }
+      }
+    }
+  }
+}
+
 void HostContentSettingsMap::RecordNumberOfExceptions() {
   for (const content_settings::WebsiteSettingsInfo* info :
        *content_settings::WebsiteSettingsRegistry::GetInstance()) {
@@ -654,6 +709,7 @@ void HostContentSettingsMap::OnContentSettingChanged(
 HostContentSettingsMap::~HostContentSettingsMap() {
   DCHECK(!prefs_);
   STLDeleteValues(&content_settings_providers_);
+  syncable_prefs::PrefModelAssociator::ResetMergeDataFinishedCallback();
 }
 
 void HostContentSettingsMap::ShutdownOnUIThread() {