Use base::BindPostTask() in components/paint_preview/*

Replace BindToTaskRunner() to with base::BindPostTask(). The only
functionality change is the base version ensures the callback is
destroyed on the bound task runner, even if the callback is never
invoked, so that any curried variables are destroyed on the right task
runner.

Bug: 1140582
Change-Id: I713f5e63a5eac63322808b75dac52693afbcdadb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2536786Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828759}

components/paint_preview/browser/paint_preview_compositor_client_impl.cc

@@ -6,44 +6,11 @@
 
 #include <utility>
 
+#include "base/bind_post_task.h"
 #include "base/callback.h"
 
 namespace paint_preview {
 
-namespace {
-
-// These methods bind a callback to a task runner. This simplifies situations
-// where a caller provides a callback which should be passed to |compositor_|
-// verbatim, but should be run on the caller's task runner rather than
-// |compositor_task_runner_|.
-//
-// Based on the implementation in: chromecast/base/bind_to_task_runner.h
-
-template <typename Sig>
-struct BindToTaskRunnerTrampoline;
-
-template <typename... Args>
-struct BindToTaskRunnerTrampoline<void(Args...)> {
-  static void Run(base::TaskRunner* task_runner,
-                  base::OnceCallback<void(Args...)> callback,
-                  Args... args) {
-    task_runner->PostTask(
-        FROM_HERE,
-        base::BindOnce(std::move(callback), std::forward<Args>(args)...));
-  }
-};
-
-template <typename T>
-base::OnceCallback<T> BindToTaskRunner(
-    scoped_refptr<base::TaskRunner> task_runner,
-    base::OnceCallback<T> callback) {
-  return base::BindOnce(&BindToTaskRunnerTrampoline<T>::Run,
-                        base::RetainedRef(std::move(task_runner)),
-                        std::move(callback));
-}
-
-}  // namespace
-
 PaintPreviewCompositorClientImpl::PaintPreviewCompositorClientImpl(
     scoped_refptr<base::SequencedTaskRunner> compositor_task_runner,
     base::WeakPtr<PaintPreviewCompositorServiceImpl> service)
@@ -91,7 +58,7 @@ void PaintPreviewCompositorClientImpl::BeginSeparatedFrameComposite(
       base::BindOnce(
           &mojom::PaintPreviewCompositor::BeginSeparatedFrameComposite,
           base::Unretained(compositor_.get()->get()), std::move(request),
-          BindToTaskRunner(default_task_runner_, std::move(callback))));
+          base::BindPostTask(default_task_runner_, std::move(callback))));
 }
 
 void PaintPreviewCompositorClientImpl::BitmapForSeparatedFrame(
@@ -112,7 +79,7 @@ void PaintPreviewCompositorClientImpl::BitmapForSeparatedFrame(
         CHECK_EQ(bitmap.colorType(), kN32_SkColorType);
         std::move(callback).Run(status, bitmap);
       },
-      BindToTaskRunner(default_task_runner_, std::move(callback)));
+      base::BindPostTask(default_task_runner_, std::move(callback)));
 
   compositor_task_runner_->PostTask(
       FROM_HERE,
@@ -130,7 +97,7 @@ void PaintPreviewCompositorClientImpl::BeginMainFrameComposite(
       base::BindOnce(
           &mojom::PaintPreviewCompositor::BeginMainFrameComposite,
           base::Unretained(compositor_.get()->get()), std::move(request),
-          BindToTaskRunner(default_task_runner_, std::move(callback))));
+          base::BindPostTask(default_task_runner_, std::move(callback))));
 }
 
 void PaintPreviewCompositorClientImpl::BitmapForMainFrame(
@@ -143,7 +110,7 @@ void PaintPreviewCompositorClientImpl::BitmapForMainFrame(
       base::BindOnce(
           &mojom::PaintPreviewCompositor::BitmapForMainFrame,
           base::Unretained(compositor_.get()->get()), clip_rect, scale_factor,
-          BindToTaskRunner(default_task_runner_, std::move(callback))));
+          base::BindPostTask(default_task_runner_, std::move(callback))));
 }
 
 void PaintPreviewCompositorClientImpl::SetRootFrameUrl(const GURL& url) {
@@ -183,7 +150,7 @@ PaintPreviewCompositorClientImpl::BuildCompositorCreatedCallback(
     base::OnceClosure user_closure,
     OnCompositorCreatedCallback service_callback) {
   DCHECK(default_task_runner_->RunsTasksInCurrentSequence());
-  return BindToTaskRunner(
+  return base::BindPostTask(
       default_task_runner_,
       base::BindOnce(&PaintPreviewCompositorClientImpl::OnCompositorCreated,
                      weak_ptr_factory_.GetWeakPtr(), std::move(user_closure),
@@ -203,7 +170,7 @@ void PaintPreviewCompositorClientImpl::OnCompositorCreated(
       base::BindOnce(
           &mojo::Remote<mojom::PaintPreviewCompositor>::set_disconnect_handler,
           base::Unretained(compositor_.get()),
-          BindToTaskRunner(
+          base::BindPostTask(
               default_task_runner_,
               base::BindOnce(
                   &PaintPreviewCompositorClientImpl::DisconnectHandler,

components/paint_preview/browser/paint_preview_compositor_service_impl.cc

@@ -4,6 +4,7 @@
 
 #include "components/paint_preview/browser/paint_preview_compositor_service_impl.h"
 
+#include "base/bind_post_task.h"
 #include "base/callback.h"
 #include "components/paint_preview/browser/compositor_utils.h"
 #include "components/paint_preview/browser/paint_preview_compositor_client_impl.h"
@@ -11,21 +12,6 @@
 
 namespace paint_preview {
 
-namespace {
-
-base::OnceClosure BindToTaskRunner(
-    scoped_refptr<base::SequencedTaskRunner> task_runner,
-    base::OnceClosure closure) {
-  return base::BindOnce(
-      [](scoped_refptr<base::SequencedTaskRunner> task_runner,
-         base::OnceClosure closure) {
-        task_runner->PostTask(FROM_HERE, std::move(closure));
-      },
-      task_runner, std::move(closure));
-}
-
-}  // namespace
-
 PaintPreviewCompositorServiceImpl::PaintPreviewCompositorServiceImpl(
     mojo::PendingRemote<mojom::PaintPreviewCompositorCollection> pending_remote,
     scoped_refptr<base::SequencedTaskRunner> compositor_task_runner_,
@@ -48,7 +34,7 @@ PaintPreviewCompositorServiceImpl::PaintPreviewCompositorServiceImpl(
             remote->set_disconnect_handler(std::move(disconnect_closure));
           },
           compositor_service_.get(), std::move(pending_remote),
-          BindToTaskRunner(
+          base::BindPostTask(
               default_task_runner_,
               base::BindOnce(
                   &PaintPreviewCompositorServiceImpl::DisconnectHandler,