Instrument serial API code to make testing easier.

chrome/browser/extensions/api/serial/serial_api.h

 // Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_SERIAL_SERIAL_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_SERIAL_SERIAL_API_H_
 #pragma once
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/extensions/api/api_function.h"
 #include "chrome/common/extensions/api/experimental_serial.h"
 #include "net/base/io_buffer.h"
 
 namespace extensions {
 
 class APIResourceEventNotifier;
+class SerialConnection;
 
 extern const char kConnectionIdKey[];
 
 class SerialGetPortsFunction : public AsyncAPIFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("experimental.serial.getPorts")
 
   SerialGetPortsFunction();
 
  protected:
@@ skipping 13 matching lines @@
 
  protected:
   virtual ~SerialOpenFunction();
 
   // AsyncAPIFunction:
   virtual bool Prepare() OVERRIDE;
   virtual void AsyncWorkStart() OVERRIDE;
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
 
+  // Overrideable for testing.

[Mihai Parparita -not on Chrome, 2012/07/11 00:45:45]

FWIW, the delegate pattern that Antony and I mentioned would be to move these
two methods into a Delegate inner class, and to default to an implementation
that returned real connections, but to allow it to be swapped out with one that
returns mocks.

The advantage of that over this is that it's more obvious what methods need to
be implemented for testing, instead of a seemingly random subset of all the
virtual methods.

+  virtual SerialConnection* CreateSerialConnection(
+      const std::string& port,
+      int bitrate,
+      APIResourceEventNotifier* event_notifier);
+  virtual bool DoesPortExist(const std::string& port);
+
  private:
   scoped_ptr<api::experimental_serial::Open::Params> params_;
   int src_id_;
   int bitrate_;
 
   // SerialConnection will take ownership.
   APIResourceEventNotifier* event_notifier_;
 };
 
 class SerialCloseFunction : public AsyncAPIFunction {
@@ skipping 66 matching lines @@
   virtual void Work() OVERRIDE;
   virtual bool Respond() OVERRIDE;
 
  private:
   scoped_ptr<api::experimental_serial::Flush::Params> params_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_SERIAL_SERIAL_API_H_