Migrate RenderProcessHostImpl from the FILE thread to task scheduler.

Bug: 689520
Change-Id: I65b372857d44c52f97986d02598c74db8d423312
Reviewed-on: https://chromium-review.googlesource.com/567783Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486194}

content/browser/hyphenation/hyphenation_impl.cc

@@ -14,6 +14,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/task_scheduler/post_task.h"
 #include "base/timer/elapsed_timer.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
@@ -66,8 +67,19 @@ void HyphenationImpl::Create(const service_manager::BindSourceInfo& source_info,
                           std::move(request));
 }
 
+// static
+scoped_refptr<base::SequencedTaskRunner> HyphenationImpl::GetTaskRunner() {
+  CR_DEFINE_STATIC_LOCAL(
+      scoped_refptr<base::SequencedTaskRunner>, runner,
+      (base::CreateSequencedTaskRunnerWithTraits(
+          {base::MayBlock(), base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
+           base::TaskPriority::USER_BLOCKING})));
+  return runner;
+}
+
 void HyphenationImpl::OpenDictionary(const std::string& locale,
                                      OpenDictionaryCallback callback) {
+  DCHECK(GetTaskRunner()->RunsTasksInCurrentSequence());
   if (IsValidLocale(locale))
     std::move(callback).Run(GetDictionaryFile(locale));
   else

content/browser/hyphenation/hyphenation_impl.h

@@ -23,6 +23,8 @@ class HyphenationImpl : public blink::mojom::Hyphenation {
   static void Create(const service_manager::BindSourceInfo& source_info,
                      blink::mojom::HyphenationRequest);
 
+  static scoped_refptr<base::SequencedTaskRunner> GetTaskRunner();
+
   // Hyphenation:
   void OpenDictionary(const std::string& locale,
                       OpenDictionaryCallback callback) override;

content/browser/mime_registry_impl.cc

@@ -20,7 +20,6 @@ MimeRegistryImpl::~MimeRegistryImpl() = default;
 void MimeRegistryImpl::Create(
     const service_manager::BindSourceInfo& source_info,
     blink::mojom::MimeRegistryRequest request) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   mojo::MakeStrongBinding(base::MakeUnique<MimeRegistryImpl>(),
                           std::move(request));
 }
@@ -28,7 +27,7 @@ void MimeRegistryImpl::Create(
 void MimeRegistryImpl::GetMimeTypeFromExtension(
     const std::string& extension,
     GetMimeTypeFromExtensionCallback callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   std::string mime_type;
   net::GetMimeTypeFromExtension(
       base::FilePath::FromUTF8Unsafe(extension).value(), &mime_type);

content/browser/mime_registry_impl.h

@@ -5,6 +5,8 @@
 #ifndef CONTENT_BROWSER_MIME_REGISTRY_IMPL_H_
 #define CONTENT_BROWSER_MIME_REGISTRY_IMPL_H_
 
+#include "base/macros.h"
+#include "base/sequence_checker.h"
 #include "third_party/WebKit/public/platform/mime_registry.mojom.h"
 
 namespace service_manager {
@@ -25,6 +27,10 @@ class MimeRegistryImpl : public blink::mojom::MimeRegistry {
   void GetMimeTypeFromExtension(
       const std::string& extension,
       GetMimeTypeFromExtensionCallback callback) override;
+
+  SEQUENCE_CHECKER(sequence_checker_);
+
+  DISALLOW_COPY_AND_ASSIGN(MimeRegistryImpl);
 };
 
 }  // namespace content

content/browser/renderer_host/render_process_host_impl.cc

@@ -318,7 +318,6 @@ void GetContexts(
 
 // Creates a file used for handing over to the renderer.
 IPC::PlatformFileForTransit CreateFileForProcess(base::FilePath file_path) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   base::File dump_file(file_path,
                        base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_APPEND);
   if (!dump_file.IsValid()) {
@@ -1641,13 +1640,14 @@ void RenderProcessHostImpl::RegisterMojoInterfaces() {
         registry.get(), base::Bind(&CreateMemoryCoordinatorHandle, GetID()));
   }
 
-  scoped_refptr<base::SingleThreadTaskRunner> file_task_runner =
-      BrowserThread::GetTaskRunnerForThread(BrowserThread::FILE);
-  registry->AddInterface(base::Bind(&MimeRegistryImpl::Create),
-                         file_task_runner);
+  registry->AddInterface(
+      base::Bind(&MimeRegistryImpl::Create),
+      base::CreateSequencedTaskRunnerWithTraits(
+          {base::MayBlock(), base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
+           base::TaskPriority::USER_BLOCKING}));
 #if BUILDFLAG(USE_MINIKIN_HYPHENATION)
   registry->AddInterface(base::Bind(&hyphenation::HyphenationImpl::Create),
-                         file_task_runner);
+                         hyphenation::HyphenationImpl::GetTaskRunner());
 #endif
 
   registry->AddInterface(base::Bind(&device::GamepadMonitor::Create));
@@ -2867,11 +2867,11 @@ void RenderProcessHostImpl::EnableAudioDebugRecordings(
 void RenderProcessHostImpl::DisableAudioDebugRecordings() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-  // Posting on the FILE thread and then replying back on the UI thread is only
-  // for avoiding races between enable and disable. Nothing is done on the FILE
-  // thread.
-  BrowserThread::PostTaskAndReply(
-      BrowserThread::FILE, FROM_HERE, base::Bind(&base::DoNothing),
+  // Posting on the sequence and then replying back on the UI thread is only
+  // for avoiding races between enable and disable. Nothing is done on the
+  // sequence.
+  GetAecDumpFileTaskRunner().PostTaskAndReply(
+      FROM_HERE, base::Bind(&base::DoNothing),
       base::Bind(&RenderProcessHostImpl::SendDisableAecDumpToRenderer,
                  weak_factory_.GetWeakPtr()));
 
@@ -3752,8 +3752,8 @@ void RenderProcessHostImpl::UnregisterAecDumpConsumerOnUIThread(int id) {
 void RenderProcessHostImpl::EnableAecDumpForId(const base::FilePath& file,
                                                int id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  BrowserThread::PostTaskAndReplyWithResult(
-      BrowserThread::FILE, FROM_HERE,
+  base::PostTaskAndReplyWithResult(
+      &GetAecDumpFileTaskRunner(), FROM_HERE,
       base::Bind(&CreateFileForProcess, file.AddExtension(IntToStringType(id))),
       base::Bind(&RenderProcessHostImpl::SendAecDumpFileToRenderer,
                  weak_factory_.GetWeakPtr(), id));
@@ -3776,6 +3776,16 @@ base::FilePath RenderProcessHostImpl::GetAecDumpFilePathWithExtensions(
   return file.AddExtension(IntToStringType(base::GetProcId(GetHandle())))
       .AddExtension(kAecDumpFileNameAddition);
 }
+
+base::SequencedTaskRunner& RenderProcessHostImpl::GetAecDumpFileTaskRunner() {
+  if (!audio_debug_recordings_file_task_runner_) {
+    audio_debug_recordings_file_task_runner_ =
+        base::CreateSequencedTaskRunnerWithTraits(
+            {base::MayBlock(), base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
+             base::TaskPriority::USER_BLOCKING});
+  }
+  return *audio_debug_recordings_file_task_runner_;
+}
 #endif  // BUILDFLAG(ENABLE_WEBRTC)
 
 void RenderProcessHostImpl::RecomputeAndUpdateWebKitPreferences() {

content/browser/renderer_host/render_process_host_impl.h

@@ -465,6 +465,7 @@ class CONTENT_EXPORT RenderProcessHostImpl
                                  IPC::PlatformFileForTransit file_for_transit);
   void SendDisableAecDumpToRenderer();
   base::FilePath GetAecDumpFilePathWithExtensions(const base::FilePath& file);
+  base::SequencedTaskRunner& GetAecDumpFileTaskRunner();
 #endif
 
   static void OnMojoError(int render_process_id, const std::string& error);
@@ -655,6 +656,9 @@ class CONTENT_EXPORT RenderProcessHostImpl
   WebRtcStopRtpDumpCallback stop_rtp_dump_callback_;
 
   WebRTCEventLogHost webrtc_eventlog_host_;
+
+  scoped_refptr<base::SequencedTaskRunner>
+      audio_debug_recordings_file_task_runner_;
 #endif
 
   // Forwards messages between WebRTCInternals in the browser process