components: Add out-of-line copy ctors for complex classes.

components/content_settings/core/common/content_settings.h

Index: components/content_settings/core/common/content_settings.h
diff --git a/components/content_settings/core/common/content_settings.h b/components/content_settings/core/common/content_settings.h
index 6352b08cf1b3c2abc0245aaabcb812ec9d35cf72..24506fa6fb104855b23d6960131b2e44d870f738 100644
--- a/components/content_settings/core/common/content_settings.h
+++ b/components/content_settings/core/common/content_settings.h
@@ -43,6 +43,7 @@ struct ContentSettingPatternSource {
                               ContentSetting setting,
                               const std::string& source,
                               bool incognito);
+  ContentSettingPatternSource(const ContentSettingPatternSource& other);
   ContentSettingPatternSource();
   ContentSettingsPattern primary_pattern;
   ContentSettingsPattern secondary_pattern;