Introduce the ENABLE_BROWSER_CDMS macro.

content/renderer/media/webmediaplayer_impl.cc

 // 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.
 
 #include "content/renderer/media/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 778 matching lines @@
     return WebMediaPlayer::MediaKeyExceptionKeySystemNotSupported;
 
   // We do not support run-time switching between key systems for now.
   if (current_key_system_.empty()) {
     if (!proxy_decryptor_) {
       proxy_decryptor_.reset(new ProxyDecryptor(
 #if defined(ENABLE_PEPPER_CDMS)
           // Create() must be called synchronously as |frame_| may not be
           // valid afterwards.
           base::Bind(&PepperCdmWrapperImpl::Create, frame_),
+#elif defined(ENABLE_BROWSER_CDMS)
+#error Browser side CDM in WMPI for prefixed EME API not supported yet.
 #endif
           BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnKeyAdded),
           BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnKeyError),
           BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnKeyMessage)));
     }
 
     GURL security_origin(frame_->document().securityOrigin().toString());
     if (!proxy_decryptor_->InitializeCDM(key_system, security_origin))
       return WebMediaPlayer::MediaKeyExceptionKeySystemNotSupported;
 
@@ skipping 570 matching lines @@
   compositor_task_runner_->PostTask(FROM_HERE,
                                     base::Bind(&GetCurrentFrameAndSignal,
                                                base::Unretained(compositor_),
                                                &video_frame,
                                                &event));
   event.Wait();
   return video_frame;
 }
 
 }  // namespace content