Reconnect support for DirectShow video capture devices in parallel to MediaFoundation ones.

media/video/capture/video_capture_device.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.
 //
 // VideoCaptureDevice is the abstract base class for realizing video capture
 // device support in Chromium. It provides the interface for OS dependent
 // implementations.
 // The class is created and functions are invoked on a thread owned by
 // VideoCaptureManager. Capturing is done on other threads, depending on the OS
 // specific implementation.
@@ skipping 37 matching lines @@
     // These operators are needed due to storing the name in an STL container.
     // In the shared build, all methods from the STL container will be exported
     // so even though they're not used, they're still depended upon.
     bool operator==(const Name& other) const {
       return other.id() == unique_id_ && other.name() == device_name_;
     }
     bool operator<(const Name& other) const {
       return unique_id_ < other.id();
     }
 
+#if defined(OS_WIN)
+    enum CaptureApiType {
+      MEDIA_FOUNDATION,
+      DIRECT_SHOW
+    };

[tommi (sloooow) - chröme, 2013/07/03 12:06:51]

nit: empty line after this one

[mcasas, 2013/07/03 12:41:10]

Done.

+    // Capture Api type is only for Windows targets.
+    const CaptureApiType& capture_api_type() const { return capture_api_type_; }

[tommi (sloooow) - chröme, 2013/07/03 12:06:51]

return by value

[mcasas, 2013/07/03 12:41:10]

Done.

+    void capture_api_type(const CaptureApiType & type) {

[tommi (sloooow) - chröme, 2013/07/03 12:06:51]

set_capture_api_type(CaptureApiType type)

note the "set_" prefix and we pass enum types by value like we do with ints.

[mcasas, 2013/07/03 12:41:10]

Done.

+      capture_api_type_ = type;
+    }
+#endif  // if defined(OS_WIN)
+
    private:
     std::string device_name_;
     std::string unique_id_;
+#if defined(OS_WIN)
+    CaptureApiType capture_api_type_;

[tommi (sloooow) - chröme, 2013/07/03 12:06:51]

right now this variable isn't initialized in the constructor.  Let's initialize
it to UNKNOWN_CAPTURE_API (or something like that) in both constructors and add
a DCHECK to capture_api_type():

CaptureApiType capture_api_type() const {
  DCHECK_NE(capture_api_type_, UNKNOWN_CAPTURE_API);
  return capture_api_type_;
}

Actually, what about removing the capture_api_type set method and instead add a
Windows-only constructor that accepts 3 arguments (adding the api selector)? 
The point is that we should be setting the API enum variable only when we first
construct the Name instance inside the respective implementation.

[mcasas, 2013/07/03 12:41:10]

The second sounds better to me.

+#endif  // if defined(OS_WIN)
     // Allow generated copy constructor and assignment.
   };
 
   // Manages a list of Name entries.
   class MEDIA_EXPORT Names
       : public NON_EXPORTED_BASE(std::list<Name>) {
    public:
     // Returns NULL if no entry was found by that ID.
     Name* FindById(const std::string& id);
 
@@ skipping 99 matching lines @@
   // not permitted to make any additional calls to its EventHandler.
   virtual void DeAllocate() = 0;
 
   // Get the name of the capture device.
   virtual const Name& device_name() = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_DEVICE_H_