[Code Health] Convert Closure to OnceClosure

The pause_cb_ Closure is a OnceClosure.  Change Pause() and Flush() to
take a OnceClosure.

This fixes text_render.cc not to use Closure.  Every instance is now
either RepeatingClosure or OnceClosure.

Bug: 1007799
Change-Id: I6ad66ccb149cac914325da98da2f4c0a3965fd7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095709Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Commit-Queue: Raymond Toy <rtoy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#750269}

media/base/text_renderer.cc

@@ -65,22 +65,22 @@ void TextRenderer::StartPlaying() {
   state_ = kPlaying;
 }
 
-void TextRenderer::Pause(const base::Closure& callback) {
+void TextRenderer::Pause(base::OnceClosure callback) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kPlaying || state_ == kEnded) << "state_ " << state_;
   DCHECK_GE(pending_read_count_, 0);
 
   if (pending_read_count_ == 0) {
     state_ = kPaused;
-    task_runner_->PostTask(FROM_HERE, callback);
+    task_runner_->PostTask(FROM_HERE, std::move(callback));
     return;
   }
 
-  pause_cb_ = callback;
+  pause_cb_ = std::move(callback);
   state_ = kPausePending;
 }
 
-void TextRenderer::Flush(const base::Closure& callback) {
+void TextRenderer::Flush(base::OnceClosure callback) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(pending_read_count_, 0);
   DCHECK(state_ == kPaused) << "state_ " << state_;
@@ -91,7 +91,7 @@ void TextRenderer::Flush(const base::Closure& callback) {
     itr->second->text_ranges_.Reset();
   }
   DCHECK_EQ(pending_eos_set_.size(), text_track_state_map_.size());
-  task_runner_->PostTask(FROM_HERE, callback);
+  task_runner_->PostTask(FROM_HERE, std::move(callback));
 }
 
 void TextRenderer::AddTextStream(DemuxerStream* text_stream,

media/base/text_renderer.h

@@ -52,10 +52,10 @@ class MEDIA_EXPORT TextRenderer {
 
   // Temporarily suspends decoding and rendering, executing |callback| when
   // playback has been suspended.
-  void Pause(const base::Closure& callback);
+  void Pause(base::OnceClosure callback);
 
   // Discards any text data, executing |callback| when completed.
-  void Flush(const base::Closure& callback);
+  void Flush(base::OnceClosure callback);
 
   // Adds new |text_stream|, having the indicated |config|, to the text stream
   // collection managed by this text renderer.
@@ -109,7 +109,7 @@ class MEDIA_EXPORT TextRenderer {
   base::RepeatingClosure ended_cb_;
 
   // Callback provided to Pause().
-  base::Closure pause_cb_;
+  base::OnceClosure pause_cb_;
 
   // Simple state tracking variable.
   enum State {

media/base/text_renderer_unittest.cc

@@ -54,9 +54,10 @@ class TextRendererTest : public testing::Test {
   void CreateTextRenderer() {
     DCHECK(!text_renderer_);
 
-    text_renderer_.reset(new TextRenderer(
-        task_environment_.GetMainThreadTaskRunner(),
-        base::Bind(&TextRendererTest::OnAddTextTrack, base::Unretained(this))));
+    text_renderer_.reset(
+        new TextRenderer(task_environment_.GetMainThreadTaskRunner(),
+                         base::BindRepeating(&TextRendererTest::OnAddTextTrack,
+                                             base::Unretained(this))));
     text_renderer_->Initialize(
         base::BindRepeating(&TextRendererTest::OnEnd, base::Unretained(this)));
   }
@@ -171,14 +172,14 @@ class TextRendererTest : public testing::Test {
 
   void Pause() {
     text_renderer_->Pause(
-        base::Bind(&TextRendererTest::OnPause, base::Unretained(this)));
+        base::BindOnce(&TextRendererTest::OnPause, base::Unretained(this)));
     base::RunLoop().RunUntilIdle();
   }
 
   void Flush() {
     EXPECT_CALL(*this, OnFlush());
     text_renderer_->Flush(
-        base::Bind(&TextRendererTest::OnFlush, base::Unretained(this)));
+        base::BindOnce(&TextRendererTest::OnFlush, base::Unretained(this)));
   }
 
   void ExpectRead(size_t idx) {
@@ -205,9 +206,10 @@ class TextRendererTest : public testing::Test {
 };
 
 TEST_F(TextRendererTest, CreateTextRendererNoInit) {
-  text_renderer_.reset(new TextRenderer(
-      task_environment_.GetMainThreadTaskRunner(),
-      base::Bind(&TextRendererTest::OnAddTextTrack, base::Unretained(this))));
+  text_renderer_.reset(
+      new TextRenderer(task_environment_.GetMainThreadTaskRunner(),
+                       base::BindRepeating(&TextRendererTest::OnAddTextTrack,
+                                           base::Unretained(this))));
   text_renderer_.reset();
 }