Refactors parts of gin:

gin/default_runner.h

Index: gin/default_runner.h
diff --git a/gin/default_runner.h b/gin/default_runner.h
new file mode 100644
index 0000000000000000000000000000000000000000..fb10e747e0328db2910d416825420efd7be97b13
--- /dev/null
+++ b/gin/default_runner.h
@@ -0,0 +1,68 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef GIN_DEFAULT_RUNNER_H_
+#define GIN_DEFAULT_RUNNER_H_
+
+#include "gin/runner.h"
+
+namespace gin {
+
+class ContextHolder;
+class DefaultRunner;
+class TryCatch;
+
+// Subclass DefaultRunnerDelegate to customize the behavior of
+// |DefaultRunner|. Typical embedders will want to subclass one of the
+// specialized DefaultRunnerDelegates, such as ModuleRunnerDelegate.
+class GIN_EXPORT DefaultRunnerDelegate {
+ public:
+  DefaultRunnerDelegate();
+  virtual ~DefaultRunnerDelegate();
+
+  // Returns the template for the global object.
+  virtual v8::Handle<v8::ObjectTemplate> GetGlobalTemplate(
+      DefaultRunner* runner,
+      v8::Isolate* isolate);
+  virtual void DidCreateContext(DefaultRunner* runner);
+  virtual void WillRunScript(DefaultRunner* runner);
+  virtual void DidRunScript(DefaultRunner* runner);
+  virtual void UnhandledException(DefaultRunner* runner, TryCatch& try_catch);
+};
+
+// DefaultRunner executes the script/functions directly in a v8::Context.
+// DefaultRunner owns a ContextHolder and v8::Context, both of which are
+// destroyed when the DefaultRunner is deleted.
+class GIN_EXPORT DefaultRunner : public Runner {
+ public:
+  DefaultRunner(DefaultRunnerDelegate* delegate, v8::Isolate* isolate);
+  virtual ~DefaultRunner();
+
+  // Before running script in this context, you'll need to enter the runner's
+  // context by creating an instance of Runner::Scope on the stack.
+
+  // Runner overrides:
+  virtual void Run(const std::string& source,
+                   const std::string& resource_name) OVERRIDE;
+  virtual v8::Handle<v8::Value> Call(v8::Handle<v8::Function> function,
+                                     v8::Handle<v8::Value> receiver,
+                                     int argc,
+                                     v8::Handle<v8::Value> argv[]) OVERRIDE;
+  virtual ContextHolder* GetContextHolder() OVERRIDE;
+
+ private:
+  friend class Scope;
+
+  void Run(v8::Handle<v8::Script> script);
+
+  DefaultRunnerDelegate* delegate_;
+
+  scoped_ptr<ContextHolder> context_holder_;
+
+  DISALLOW_COPY_AND_ASSIGN(DefaultRunner);
+};
+
+}  // namespace gin
+
+#endif  // GIN_DEFAULT_RUNNER_H_