VideoCaptureManager: handle case when GetDeviceEntryBySessionId is null

content/browser/renderer_host/media/video_capture_manager.cc

 // 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.
 
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
@@ skipping 532 matching lines @@
 
     if (entry->stream_type == MEDIA_DESKTOP_VIDEO_CAPTURE) {
       const media::VideoCaptureSessionId session_id =
           device_start_queue_.front().session_id();
       DCHECK(session_id != kFakeSessionId);
       MaybePostDesktopCaptureWindowId(session_id);
     }
 
     auto request = photo_request_queue_.begin();
     while(request != photo_request_queue_.end()) {
-      if (GetDeviceEntryBySessionId(request->first)->video_capture_device()) {
-        request->second.Run(entry->video_capture_device());
+      DeviceEntry* maybe_entry = GetDeviceEntryBySessionId(request->first);
+      if (maybe_entry && maybe_entry->video_capture_device()) {
+        request->second.Run(maybe_entry->video_capture_device());
         photo_request_queue_.erase(request);
       }
       ++request;
     }
   }
 
   device_start_queue_.pop_front();
   HandleQueuedStartRequest();
 }
 
@@ skipping 717 matching lines @@
     if (!device_in_queue) {
       // Session ID is only valid for Screen capture. So we can fake it to
       // resume video capture devices here.
       QueueStartDevice(kFakeSessionId, entry.get(), entry->parameters);
     }
   }
 }
 #endif  // defined(OS_ANDROID)
 
 }  // namespace content