Remove LazyInstance usage from media/

media/filters/ffmpeg_glue.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 "media/filters/ffmpeg_glue.h"
 
-#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/synchronization/lock.h"
 #include "media/base/container_names.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 
 namespace media {
 
 // Internal buffer size used by AVIO for reading.
@@ skipping 62 matching lines @@
       return 0;
 
     case AV_LOCK_DESTROY:
       delete static_cast<base::Lock*>(*lock);
       *lock = nullptr;
       return 0;
   }
   return 1;
 }
 
-// FFmpeg must only be initialized once, so use a LazyInstance to ensure this.
-class FFmpegInitializer {
- public:
-  bool initialized() { return initialized_; }
+// FFmpeg must only be initialized once per process.
+static bool InitializeInternal() {
+  // Register our protocol glue code with FFmpeg.
+  if (av_lockmgr_register(&LockManagerOperation) != 0)
+    return false;
 
- private:
-  friend struct base::DefaultLazyInstanceTraits<FFmpegInitializer>;
+  // Now register the rest of FFmpeg.
+  av_register_all();
+  return true;
+}
 
-  FFmpegInitializer()
-      : initialized_(false) {
-    // Register our protocol glue code with FFmpeg.
-    if (av_lockmgr_register(&LockManagerOperation) != 0)
-      return;
-
-    // Now register the rest of FFmpeg.
-    av_register_all();
-
-    initialized_ = true;
-  }
-
-  ~FFmpegInitializer() {
-    NOTREACHED() << "FFmpegInitializer should be leaky!";
-  }
-
-  bool initialized_;
-
-  DISALLOW_COPY_AND_ASSIGN(FFmpegInitializer);
-};
-
-static base::LazyInstance<FFmpegInitializer>::Leaky g_lazy_instance =
-    LAZY_INSTANCE_INITIALIZER;
 void FFmpegGlue::InitializeFFmpeg() {
-  // Get() will invoke the FFmpegInitializer constructor once.
-  CHECK(g_lazy_instance.Get().initialized());
+  static bool initialized = InitializeInternal();

[scottmg, 2017/01/31 21:10:34]

Could consider inlining the Internal() function here with a [](){} similar to
the other one.

[Mark Mentovai, 2017/01/31 21:33:56]

You can eliminate InitializeInternal() by writing its body here with a lambda:

  static bool initialized = [](){
    /* … */
    return true;
  }();

[DaleCurtis, 2017/01/31 22:04:33]

Thanks, done!

+  CHECK(initialized);
 }
 
 FFmpegGlue::FFmpegGlue(FFmpegURLProtocol* protocol)
     : open_called_(false) {
   InitializeFFmpeg();
 
   // Initialize an AVIOContext using our custom read and seek operations.  Don't
   // keep pointers to the buffer since FFmpeg may reallocate it on the fly.  It
   // will be cleaned up
   format_context_ = avformat_alloc_context();
@@ skipping 62 matching lines @@
     avformat_free_context(format_context_);
     av_free(avio_context_->buffer);
     return;
   }
 
   avformat_close_input(&format_context_);
   av_free(avio_context_->buffer);
 }
 
 }  // namespace media