[Paint Preview] Make PaintPreviewBaseService::StartCompositorService static

Change-Id: I021f64713a2b19b9e40f5ddab7258a3fc97fd88a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2357454Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798615}

chrome/browser/paint_preview/paint_preview_compositor_browsertest.cc

@@ -113,9 +113,8 @@ IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest,
 
 IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest, CompositorCreate) {
   CreateServiceInstance();
-  auto* base_service = GetBaseService();
-  auto compositor_service = ToCompositorServiceImpl(
-      base_service->StartCompositorService(base::DoNothing()));
+  auto compositor_service =
+      ToCompositorServiceImpl(StartCompositorService(base::DoNothing()));
 
   base::RunLoop loop;
   auto compositor = ToCompositorClientImpl(
@@ -133,9 +132,8 @@ IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest, CompositorCreate) {
 IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest,
                        MultipleCompositorCreate) {
   CreateServiceInstance();
-  auto* base_service = GetBaseService();
-  auto compositor_service = ToCompositorServiceImpl(
-      base_service->StartCompositorService(base::DoNothing()));
+  auto compositor_service =
+      ToCompositorServiceImpl(StartCompositorService(base::DoNothing()));
   EXPECT_EQ(0U, compositor_service->ActiveClientsForTesting().size());
   EXPECT_FALSE(compositor_service->HasActiveClients());
 
@@ -174,12 +172,11 @@ IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest,
 IN_PROC_BROWSER_TEST_F(PaintPreviewCompositorBrowserTest,
                        KillWithActiveCompositors) {
   CreateServiceInstance();
-  auto* base_service = GetBaseService();
   // NOTE: the disconnect handler for the service as a whole only triggers if
   // the service is killed unexpectedly. Here the |compositor_service| object
   // is deleted (performing a graceful shutdown) so the handler won't run.
-  auto compositor_service = ToCompositorServiceImpl(
-      base_service->StartCompositorService(base::DoNothing()));
+  auto compositor_service =
+      ToCompositorServiceImpl(StartCompositorService(base::DoNothing()));
 
   base::RunLoop loop;
   auto compositor = ToCompositorClientImpl(

components/paint_preview/browser/compositor_utils.cc

@@ -9,6 +9,7 @@
 #include "base/bind.h"
 #include "build/build_config.h"
 #include "components/discardable_memory/service/discardable_shared_memory_manager.h"
+#include "components/paint_preview/browser/paint_preview_compositor_service_impl.h"
 #include "components/paint_preview/browser/service_sandbox_type.h"
 #include "components/services/paint_preview_compositor/public/mojom/paint_preview_compositor.mojom.h"
 #include "components/strings/grit/components_strings.h"
@@ -31,6 +32,31 @@ void BindDiscardableSharedMemoryManagerOnIOThread(
 
 }  // namespace
 
+std::unique_ptr<PaintPreviewCompositorService> StartCompositorService(
+    base::OnceClosure disconnect_handler) {
+  // Create a dedicated sequence for communicating with the compositor. This
+  // sequence will handle message serialization/deserialization of bitmaps so it
+  // affects user visible elements. This is an implementation detail and the
+  // caller should continue to communicate with the compositor via the sequence
+  // that called this.
+  auto compositor_task_runner = base::ThreadPool::CreateSequencedTaskRunner(
+      {base::TaskPriority::USER_VISIBLE,
+       base::ThreadPolicy::MUST_USE_FOREGROUND});
+
+  // The discardable memory manager isn't initialized here. This is handled in
+  // the constructor of PaintPreviewCompositorServiceImpl once the pending
+  // remote becomes bound.
+  mojo::PendingRemote<mojom::PaintPreviewCompositorCollection> pending_remote;
+  compositor_task_runner->PostTask(
+      FROM_HERE,
+      base::BindOnce(&CreateCompositorCollectionPending,
+                     pending_remote.InitWithNewPipeAndPassReceiver()));
+
+  return std::make_unique<PaintPreviewCompositorServiceImpl>(
+      std::move(pending_remote), compositor_task_runner,
+      std::move(disconnect_handler));
+}
+
 mojo::Remote<mojom::PaintPreviewCompositorCollection>
 CreateCompositorCollection() {
   mojo::Remote<mojom::PaintPreviewCompositorCollection> collection;

components/paint_preview/browser/compositor_utils.h

@@ -5,11 +5,16 @@
 #ifndef COMPONENTS_PAINT_PREVIEW_BROWSER_COMPOSITOR_UTILS_H_
 #define COMPONENTS_PAINT_PREVIEW_BROWSER_COMPOSITOR_UTILS_H_
 
+#include "components/paint_preview/public/paint_preview_compositor_service.h"
 #include "components/services/paint_preview_compositor/public/mojom/paint_preview_compositor.mojom.h"
 #include "mojo/public/cpp/bindings/remote.h"
 
 namespace paint_preview {
 
+// Starts the compositor service in a utility process.
+std::unique_ptr<PaintPreviewCompositorService> StartCompositorService(
+    base::OnceClosure disconnect_handler);
+
 // Creates a utility process via the service manager that is sandboxed and
 // running an instance of the PaintPreviewCompositorCollectionImpl. This can be
 // used to create compositor instances that composite Paint Previews into

components/paint_preview/browser/paint_preview_base_service.cc

@@ -18,7 +18,6 @@
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/paint_preview/browser/compositor_utils.h"
 #include "components/paint_preview/browser/paint_preview_client.h"
-#include "components/paint_preview/browser/paint_preview_compositor_service_impl.h"
 #include "components/paint_preview/common/mojom/paint_preview_recorder.mojom.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
@@ -115,32 +114,6 @@ void PaintPreviewBaseService::CapturePaintPreview(
                      start_time, std::move(callback)));
 }
 
-std::unique_ptr<PaintPreviewCompositorService>
-PaintPreviewBaseService::StartCompositorService(
-    base::OnceClosure disconnect_handler) {
-  // Create a dedicated sequence for communicating with the compositor. This
-  // sequence will handle message serialization/deserialization of bitmaps so it
-  // affects user visible elements. This is an implementation detail and the
-  // caller should continue to communicate with the compositor via the sequence
-  // that called this.
-  auto compositor_task_runner = base::ThreadPool::CreateSequencedTaskRunner(
-      {base::TaskPriority::USER_VISIBLE,
-       base::ThreadPolicy::MUST_USE_FOREGROUND});
-
-  // The discardable memory manager isn't initialized here. This is handled in
-  // the constructor of PaintPreviewCompositorServiceImpl once the pending
-  // remote becomes bound.
-  mojo::PendingRemote<mojom::PaintPreviewCompositorCollection> pending_remote;
-  compositor_task_runner->PostTask(
-      FROM_HERE,
-      base::BindOnce(&CreateCompositorCollectionPending,
-                     pending_remote.InitWithNewPipeAndPassReceiver()));
-
-  return std::make_unique<PaintPreviewCompositorServiceImpl>(
-      std::move(pending_remote), compositor_task_runner,
-      std::move(disconnect_handler));
-}
-
 void PaintPreviewBaseService::OnCaptured(
     int frame_tree_node_id,
     base::TimeTicks start_time,

components/paint_preview/browser/paint_preview_base_service.h

@@ -24,7 +24,6 @@
 #include "components/paint_preview/common/file_utils.h"
 #include "components/paint_preview/common/mojom/paint_preview_recorder.mojom.h"
 #include "components/paint_preview/common/proto/paint_preview.pb.h"
-#include "components/paint_preview/public/paint_preview_compositor_service.h"
 #include "content/public/browser/web_contents.h"
 
 namespace paint_preview {
@@ -128,10 +127,6 @@ class PaintPreviewBaseService : public KeyedService {
                            size_t max_per_capture_size,
                            OnCapturedCallback callback);
 
-  // Starts the compositor service in a utility process.
-  std::unique_ptr<PaintPreviewCompositorService> StartCompositorService(
-      base::OnceClosure disconnect_handler);
-
  private:
   void OnCaptured(int frame_tree_node_id,
                   base::TimeTicks start_time,

components/paint_preview/player/player_compositor_delegate.cc

@@ -113,10 +113,9 @@ PlayerCompositorDelegate::PlayerCompositorDelegate(
   TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("paint_preview",
                                     "PlayerCompositorDelegate CreateCompositor",
                                     TRACE_ID_LOCAL(this));
-  paint_preview_compositor_service_ =
-      paint_preview_service_->StartCompositorService(base::BindOnce(
-          &PlayerCompositorDelegate::OnCompositorServiceDisconnected,
-          weak_factory_.GetWeakPtr()));
+  paint_preview_compositor_service_ = StartCompositorService(
+      base::BindOnce(&PlayerCompositorDelegate::OnCompositorServiceDisconnected,
+                     weak_factory_.GetWeakPtr()));
 
   paint_preview_compositor_client_ =
       paint_preview_compositor_service_->CreateCompositor(