Replace base::Callback in multibuffer source.

The callback (init_cb_) is effectively called only once. This is guaranteed by the std::move():
https://cs.chromium.org/chromium/src/media/blink/multibuffer_data_source.cc?rcl=8d2d53d6df3c7347f9d4c32074540b990a8f1736&l=631

This is part of the base::Callback migration.

Context: https://cs.chromium.org/chromium/src/docs/callback.md?rcl=9fcc3764aea8f97e9f6de4a9ee61d554e67edcda&l=40
Change-Id: I1ba81f8b281339cf514baa7f6739425bb9b9988c
Bug: 714018
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2030962
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Auto-Submit: Jose Lopes <jabolopes@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741166}

media/blink/multibuffer_data_source.cc

@@ -190,12 +190,12 @@ void MultibufferDataSource::CreateResourceLoader_Locked(
   UpdateBufferSizes();
 }
 
-void MultibufferDataSource::Initialize(const InitializeCB& init_cb) {
+void MultibufferDataSource::Initialize(InitializeCB init_cb) {
   DCHECK(render_task_runner_->BelongsToCurrentThread());
   DCHECK(init_cb);
   DCHECK(!reader_.get());
 
-  init_cb_ = init_cb;
+  init_cb_ = std::move(init_cb);
 
   CreateResourceLoader(0, kPositionNotSpecified);
 

media/blink/multibuffer_data_source.h

@@ -66,8 +66,8 @@ class MEDIA_BLINK_EXPORT MultibufferDataSource : public DataSource {
   // Executes |init_cb| with the result of initialization when it has completed.
   //
   // Method called on the render thread.
-  typedef base::Callback<void(bool)> InitializeCB;
-  void Initialize(const InitializeCB& init_cb);
+  using InitializeCB = base::OnceCallback<void(bool)>;
+  void Initialize(InitializeCB init_cb);
 
   // Adjusts the buffering algorithm based on the given preload value.
   void SetPreload(Preload preload);

media/blink/multibuffer_data_source_unittest.cc

@@ -235,7 +235,7 @@ class MultibufferDataSourceTest : public testing::Test {
 
     response_generator_.reset(new TestResponseGenerator(gurl, file_size));
     EXPECT_CALL(*this, OnInitialize(expected));
-    data_source_->Initialize(base::Bind(
+    data_source_->Initialize(base::BindOnce(
         &MultibufferDataSourceTest::OnInitialize, base::Unretained(this)));
     base::RunLoop().RunUntilIdle();
 
@@ -1000,7 +1000,7 @@ TEST_F(MultibufferDataSourceTest, Http_ShareData) {
   // This call would not be expected if we were not sharing data.
   EXPECT_CALL(host2, SetTotalBytes(response_generator_->content_length()));
   EXPECT_CALL(host2, AddBufferedByteRange(0, kDataSize * 2));
-  source2.Initialize(base::Bind(&MultibufferDataSourceTest::OnInitialize,
+  source2.Initialize(base::BindOnce(&MultibufferDataSourceTest::OnInitialize,
                                     base::Unretained(this)));
   base::RunLoop().RunUntilIdle();
 
@@ -1362,8 +1362,8 @@ TEST_F(MultibufferDataSourceTest, SeekPastEOF) {
 
   response_generator_.reset(new TestResponseGenerator(gurl, kDataSize + 1));
   EXPECT_CALL(*this, OnInitialize(true));
-  data_source_->Initialize(base::Bind(&MultibufferDataSourceTest::OnInitialize,
-                                      base::Unretained(this)));
+  data_source_->Initialize(base::BindOnce(
+      &MultibufferDataSourceTest::OnInitialize, base::Unretained(this)));
   base::RunLoop().RunUntilIdle();
 
   // Not really loading until after OnInitialize is called.
@@ -1738,8 +1738,8 @@ TEST_F(MultibufferDataSourceTest, Http_CheckLoadingTransition) {
 
   response_generator_.reset(new TestResponseGenerator(gurl, kDataSize * 1));
   EXPECT_CALL(*this, OnInitialize(true));
-  data_source_->Initialize(base::Bind(&MultibufferDataSourceTest::OnInitialize,
-                                      base::Unretained(this)));
+  data_source_->Initialize(base::BindOnce(
+      &MultibufferDataSourceTest::OnInitialize, base::Unretained(this)));
   base::RunLoop().RunUntilIdle();
 
   // Not really loading until after OnInitialize is called.

media/blink/webmediaplayer_impl.cc

@@ -733,7 +733,7 @@ void WebMediaPlayerImpl::DoLoad(LoadType load_type,
     mb_data_source_->SetPreload(preload_);
     mb_data_source_->SetIsClientAudioElement(client_->IsAudioElement());
     mb_data_source_->Initialize(
-        base::Bind(&WebMediaPlayerImpl::DataSourceInitialized, weak_this_));
+        base::BindOnce(&WebMediaPlayerImpl::DataSourceInitialized, weak_this_));
   }
 }