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

components/content_settings/core/common/content_settings_pattern.h

Index: components/content_settings/core/common/content_settings_pattern.h
diff --git a/components/content_settings/core/common/content_settings_pattern.h b/components/content_settings/core/common/content_settings_pattern.h
index f85c648bfc036aa9ac0261d0aa3cb62ed0d5318f..b5b83529b00f92b431157744a22fa4e9abebb3bb 100644
--- a/components/content_settings/core/common/content_settings_pattern.h
+++ b/components/content_settings/core/common/content_settings_pattern.h
@@ -129,6 +129,7 @@ class ContentSettingsPattern {
 
   // Returns a pattern that matches the scheme and host of this URL, as well as
   // all subdomains and ports.
+  // TODO(lshang): Remove this when crbug.com/604612 is done.
   static ContentSettingsPattern FromURL(const GURL& url);
 
   // Returns a pattern that matches exactly this URL.
@@ -145,6 +146,13 @@ class ContentSettingsPattern {
   //   - [a:b:c:d:e:f:g:h] (matches an exact IPv6 ip)
   static ContentSettingsPattern FromString(const std::string& pattern_spec);
 
+  // Migrate domain scoped settings generated using FromURL() to be origin
+  // scoped. Return false if domain_pattern is not generated using FromURL().
+  // TODO(lshang): Remove this when migration is done. https://crbug.com/604612
+  static bool MigrateFromDomainToOrigin(
+      const ContentSettingsPattern& domain_pattern,
+      ContentSettingsPattern* origin_pattern);
+
   // Sets the scheme that doesn't support domain wildcard and port.
   // Needs to be called by the embedder before using ContentSettingsPattern.
   // |scheme| can't be NULL, and the pointed string must remain alive until the