[Extensions] Parse schema string directly into a v8 object

extensions/common/extension_api.h

Index: extensions/common/extension_api.h
diff --git a/extensions/common/extension_api.h b/extensions/common/extension_api.h
index 113f41a08c079bfe27745c3dce266fbafa831b3b..0a8aef71d794ca738a8ea4f7456112e8f250f7a8 100644
--- a/extensions/common/extension_api.h
+++ b/extensions/common/extension_api.h
@@ -104,8 +104,13 @@ class ExtensionAPI {
   // Returns true if |name| is available to WebUI contexts on |url|.
   bool IsAvailableToWebUI(const std::string& name, const GURL& url);
 
+  // Gets the StringPiece for the schema specified by |api_name|.
+  base::StringPiece GetSchemaStringPiece(const std::string& api_name);
+
   // Gets the schema for the extension API with namespace |full_name|.
   // Ownership remains with this object.
+  // TODO(devlin): Now that we use GetSchemaStringPiece() in the renderer, we
+  // may not really need this anymore.
   const base::DictionaryValue* GetSchema(const std::string& full_name);
 
   // Splits a full name from the extension API into its API and child name
@@ -144,6 +149,9 @@ class ExtensionAPI {
       std::map<std::string, std::unique_ptr<const base::DictionaryValue>>;
   SchemaMap schemas_;
 
+  using StringPieceMap = std::map<std::string, base::StringPiece>;
+  StringPieceMap schema_strings_;
+
   // FeatureProviders used for resolving dependencies.
   typedef std::map<std::string, const FeatureProvider*> FeatureProviderMap;
   FeatureProviderMap dependency_providers_;