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

components/content_settings/core/common/content_settings_pattern.cc

Index: components/content_settings/core/common/content_settings_pattern.cc
diff --git a/components/content_settings/core/common/content_settings_pattern.cc b/components/content_settings/core/common/content_settings_pattern.cc
index 74a9ffaf86d16c055e4613fe3daac1f076becb74..d6dd272f3a8fe8968f03daebd22d6b3863e518f6 100644
--- a/components/content_settings/core/common/content_settings_pattern.cc
+++ b/components/content_settings/core/common/content_settings_pattern.cc
@@ -439,6 +439,60 @@ ContentSettingsPattern ContentSettingsPattern::FromString(
 }
 
 // static
+bool ContentSettingsPattern::MigrateFromDomainToOrigin(
+    const ContentSettingsPattern& domain_pattern,
+    ContentSettingsPattern* origin_pattern) {
+  DCHECK(origin_pattern);
+
+  // Generated patterns with ::FromURL (which we want to migrate) must either
+  // have a scheme wildcard or be https.
+  if (domain_pattern.parts_.scheme != url::kHttpsScheme &&
+      !domain_pattern.parts_.is_scheme_wildcard) {
+    return false;
+  }
+
+  // Generated patterns using ::FromURL with the HTTPs scheme can not have a
+  // port wildcard.
+  if (domain_pattern.parts_.is_port_wildcard &&
+      domain_pattern.parts_.scheme == url::kHttpsScheme) {
+    return false;
+  }
+
+  // Patterns generated with ::FromURL will always have a domain wildcard. Those
+  // generated with ::FromURLNoWildcard don't.
+  if (!domain_pattern.parts_.has_domain_wildcard)
+    return false;
+
+  // Generated patterns with ::FromURL will always have a host.
+  if (domain_pattern.parts_.host.empty())
+    return false;
+
+  std::unique_ptr<ContentSettingsPattern::BuilderInterface> builder(
+      ContentSettingsPattern::CreateBuilder(false));
+
+  if (domain_pattern.parts_.is_scheme_wildcard)
+    builder->WithScheme(url::kHttpScheme);
+  else
+    builder->WithScheme(domain_pattern.parts_.scheme);
+
+  builder->WithHost(domain_pattern.parts_.host);
+
+  if (domain_pattern.parts_.is_port_wildcard) {
+    if (domain_pattern.parts_.scheme == url::kHttpsScheme) {
+      builder->WithPort(GetDefaultPort(url::kHttpsScheme));
+    } else {
+      builder->WithPort(GetDefaultPort(url::kHttpScheme));
+    }
+  } else {
+    builder->WithPort(domain_pattern.parts_.port);
+  }
+
+  *origin_pattern = builder->Build();
+
+  return true;
+}
+
+// static
 void ContentSettingsPattern::SetNonWildcardDomainNonPortScheme(
     const char* scheme) {
   DCHECK(scheme);