Revert of ios: Remove use of MessageLoopProxy and deprecated MessageLoop APIs...

Revert of ios: Remove use of MessageLoopProxy and deprecated MessageLoop APIs (patchset #3 id:40001 of https://codereview.chromium.org/1160403005/)

Reason for revert:
Broke IOS_Device compile.
https://build.chromium.org/p/chromium.mac/builders/iOS_Device/builds/8802

Original issue's description:
> ios: Remove use of MessageLoopProxy and deprecated MessageLoop APIs
>
> BUG=465354
>
> Committed: https://crrev.com/9c8e5d7259661cda32b698ee88254491e6984900
> Cr-Commit-Position: refs/heads/master@{#333080}

TBR=stuartmorgan@chromium.org,skyostil@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=465354

Review URL: https://codereview.chromium.org/1167533009

Cr-Commit-Position: refs/heads/master@{#333083}

ios/chrome/browser/net/retryable_url_fetcher_unittest.mm

@@ -60,7 +60,7 @@ class RetryableURLFetcherTest : public PlatformTest {
 
 TEST_F(RetryableURLFetcherTest, TestResponse200) {
   scoped_refptr<net::URLRequestContextGetter> request_context_getter =
-      new net::TestURLRequestContextGetter(message_loop_.task_runner());
+      new net::TestURLRequestContextGetter(message_loop_.message_loop_proxy());
   base::scoped_nsobject<RetryableURLFetcher> retryableFetcher(
       [[RetryableURLFetcher alloc]
           initWithRequestContextGetter:request_context_getter.get()
@@ -81,7 +81,7 @@ TEST_F(RetryableURLFetcherTest, TestResponse200) {
 
 TEST_F(RetryableURLFetcherTest, TestResponse404) {
   scoped_refptr<net::URLRequestContextGetter> request_context_getter =
-      new net::TestURLRequestContextGetter(message_loop_.task_runner());
+      new net::TestURLRequestContextGetter(message_loop_.message_loop_proxy());
   base::scoped_nsobject<RetryableURLFetcher> retryableFetcher(
       [[RetryableURLFetcher alloc]
           initWithRequestContextGetter:request_context_getter.get()

ios/chrome/browser/snapshots/snapshot_cache.mm

@@ -212,8 +212,8 @@ void ConvertAndSaveGreyImage(
   }
 
   base::PostTaskAndReplyWithResult(
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::FILE_USER_BLOCKING)
-          .get(),
+      web::WebThread::GetMessageLoopProxyForThread(
+          web::WebThread::FILE_USER_BLOCKING).get(),
       FROM_HERE, base::BindBlock(^base::scoped_nsobject<UIImage>() {
         // Retrieve the image on a high priority thread.
         return base::scoped_nsobject<UIImage>([ReadImageFromDisk(
@@ -401,9 +401,10 @@ void ConvertAndSaveGreyImage(
   // already in the cache, use it.
   UIImage* img = [imageDictionary_ objectForKey:sessionID];
   base::PostTaskAndReplyWithResult(
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::FILE_USER_BLOCKING)
-          .get(),
-      FROM_HERE, base::BindBlock(^base::scoped_nsobject<UIImage>() {
+      web::WebThread::GetMessageLoopProxyForThread(
+          web::WebThread::FILE_USER_BLOCKING).get(),
+      FROM_HERE,
+      base::BindBlock(^base::scoped_nsobject<UIImage>() {
         base::scoped_nsobject<UIImage> result([img retain]);
         // If the image is not in the cache, load it from disk.
         if (!result)
@@ -464,9 +465,10 @@ void ConvertAndSaveGreyImage(
   }
 
   base::PostTaskAndReplyWithResult(
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::FILE_USER_BLOCKING)
-          .get(),
-      FROM_HERE, base::BindBlock(^base::scoped_nsobject<UIImage>() {
+      web::WebThread::GetMessageLoopProxyForThread(
+          web::WebThread::FILE_USER_BLOCKING).get(),
+      FROM_HERE,
+      base::BindBlock(^base::scoped_nsobject<UIImage>() {
         // Retrieve the image on a high priority thread.
         // Loading the file into NSData is more reliable.
         // -imageWithContentsOfFile would ocassionally claim the image was not a

ios/crnet/crnet_environment.mm

@@ -55,21 +55,21 @@ class CrNetURLRequestContextGetter : public net::URLRequestContextGetter {
  public:
   CrNetURLRequestContextGetter(
       net::URLRequestContext* context,
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
-      : context_(context), task_runner_(task_runner) {}
+      const scoped_refptr<base::MessageLoopProxy>& loop)
+      : context_(context), loop_(loop) {}
 
   net::URLRequestContext* GetURLRequestContext() override { return context_; }
 
   scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
       const override {
-    return task_runner_;
+    return loop_;
   }
  private:
   // Must be called on the IO thread.
   ~CrNetURLRequestContextGetter() override {}
 
   net::URLRequestContext* context_;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::MessageLoopProxy> loop_;
   DISALLOW_COPY_AND_ASSIGN(CrNetURLRequestContextGetter);
 };
 
@@ -260,7 +260,7 @@ void CrNetEnvironment::Install() {
   // delegates will receive callbacks.
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
   proxy_config_service_.reset(net::ProxyService::CreateSystemProxyConfigService(
-      network_io_thread_->task_runner(), nullptr));
+      network_io_thread_->message_loop_proxy(), nullptr));
 
   PostToNetworkThread(FROM_HERE,
       base::Bind(&CrNetEnvironment::InitializeOnNetworkThread,
@@ -268,7 +268,7 @@ void CrNetEnvironment::Install() {
 
   net::SetURLRequestContextForNSSHttpIO(main_context_.get());
   main_context_getter_ = new CrNetURLRequestContextGetter(
-      main_context_.get(), network_io_thread_->task_runner());
+      main_context_.get(), network_io_thread_->message_loop_proxy());
   SetRequestFilterBlock(nil);
   net_log_started_ = false;
 }
@@ -310,7 +310,7 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
   net::RequestTracker::AddGlobalNetworkClientFactory(
       [[[WebPNetworkClientFactory alloc]
           initWithTaskRunner:file_user_blocking_thread_
-                                 ->task_runner()] autorelease]);
+                                 ->message_loop_proxy()] autorelease]);
 
 #if 0
   // TODO(huey): Re-enable this once SDCH supports SSL and dictionaries from
@@ -373,10 +373,12 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
       base::mac::NSStringToFilePath([dirs objectAtIndex:0]);
   cache_path = cache_path.Append(FILE_PATH_LITERAL("crnet"));
   net::HttpCache::DefaultBackend* main_backend =
-      new net::HttpCache::DefaultBackend(net::DISK_CACHE,
-                                         net::CACHE_BACKEND_DEFAULT, cache_path,
-                                         0,  // Default cache size.
-                                         network_cache_thread_->task_runner());
+      new net::HttpCache::DefaultBackend(
+          net::DISK_CACHE,
+          net::CACHE_BACKEND_DEFAULT,
+          cache_path,
+          0,  // Default cache size.
+          network_cache_thread_->message_loop_proxy());
 
   net::HttpNetworkSession::Params params;
   params.host_resolver = main_context_->host_resolver();
@@ -419,7 +421,7 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
       new net::URLRequestJobFactoryImpl;
   job_factory->SetProtocolHandler("data", new net::DataProtocolHandler);
   job_factory->SetProtocolHandler(
-      "file", new net::FileProtocolHandler(file_thread_->task_runner()));
+      "file", new net::FileProtocolHandler(file_thread_->message_loop_proxy()));
   main_context_->set_job_factory(job_factory);
 }
 

ios/net/cookies/cookie_store_ios.mm

@@ -15,13 +15,13 @@
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/observer_list.h"
 #include "base/sequenced_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/task_runner_util.h"
-#include "base/thread_task_runner_handle.h"
 #include "base/threading/thread_restrictions.h"
 #include "ios/net/cookies/cookie_creation_time_manager.h"
 #include "ios/net/cookies/cookie_store_ios_client.h"
@@ -798,7 +798,7 @@ void CookieStoreIOS::OnSystemCookiesChanged() {
 
   flush_closure_.Reset(base::Bind(&CookieStoreIOS::Flush,
                                   base::Unretained(this), base::Closure()));
-  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+  base::MessageLoopProxy::current()->PostDelayedTask(
       FROM_HERE, flush_closure_.callback(), flush_delay_);
 }
 

ios/web/public/web_thread.h

@@ -11,6 +11,7 @@
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/task_runner_util.h"
 
 namespace base {
@@ -83,8 +84,8 @@ class WebThread {
 
     // NOTE: do not add new threads here that are only used by a small number of
     // files. Instead you should just use a Thread class and pass its
-    // SingleThreadTaskRunner around. Named threads there are only for threads
-    // that are used in many places.
+    // MessageLoopProxy around. Named threads there are only for threads that
+    // are used in many places.
 
     // This identifier does not represent a thread.  Instead it counts the
     // number of well-known threads.  Insert new well-known threads before this
@@ -123,17 +124,18 @@ class WebThread {
       const tracked_objects::Location& from_here,
       const base::Callback<ReturnType(void)>& task,
       const base::Callback<void(ReplyArgType)>& reply) {
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner =
-        GetTaskRunnerForThread(identifier);
-    return base::PostTaskAndReplyWithResult(task_runner.get(), from_here, task,
-                                            reply);
+    scoped_refptr<base::MessageLoopProxy> message_loop_proxy =
+        GetMessageLoopProxyForThread(identifier);
+    return base::PostTaskAndReplyWithResult(message_loop_proxy.get(), from_here,
+                                            task, reply);
   }
 
   template <class T>
   static bool DeleteSoon(ID identifier,
                          const tracked_objects::Location& from_here,
                          const T* object) {
-    return GetTaskRunnerForThread(identifier)->DeleteSoon(from_here, object);
+    return GetMessageLoopProxyForThread(identifier)
+        ->DeleteSoon(from_here, object);
   }
 
   // Simplified wrappers for posting to the blocking thread pool. Use this
@@ -200,9 +202,9 @@ class WebThread {
   // sets identifier to its ID.
   static bool GetCurrentThreadIdentifier(ID* identifier) WARN_UNUSED_RESULT;
 
-  // Callers can hold on to a refcounted SingleThreadTaskRunner beyond the
-  // lifetime of the thread.
-  static scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunnerForThread(
+  // Callers can hold on to a refcounted MessageLoopProxy beyond the lifetime
+  // of the thread.
+  static scoped_refptr<base::MessageLoopProxy> GetMessageLoopProxyForThread(
       ID identifier);
 
   // Returns an appropriate error message for when

ios/web/shell/shell_browser_state.mm

@@ -20,9 +20,9 @@ ShellBrowserState::ShellBrowserState() : BrowserState() {
 
   request_context_getter_ = new ShellURLRequestContextGetter(
       GetStatePath(),
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::IO),
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::FILE),
-      web::WebThread::GetTaskRunnerForThread(web::WebThread::CACHE));
+      web::WebThread::GetMessageLoopProxyForThread(web::WebThread::IO),
+      web::WebThread::GetMessageLoopProxyForThread(web::WebThread::FILE),
+      web::WebThread::GetMessageLoopProxyForThread(web::WebThread::CACHE));
 }
 
 ShellBrowserState::~ShellBrowserState() {

ios/web/shell/shell_url_request_context_getter.cc

@@ -40,7 +40,7 @@ ShellURLRequestContextGetter::ShellURLRequestContextGetter(
     const base::FilePath& base_path,
     const scoped_refptr<base::SingleThreadTaskRunner>& network_task_runner,
     const scoped_refptr<base::SingleThreadTaskRunner>& file_task_runner,
-    const scoped_refptr<base::SingleThreadTaskRunner>& cache_task_runner)
+    const scoped_refptr<base::MessageLoopProxy>& cache_task_runner)
     : base_path_(base_path),
       file_task_runner_(file_task_runner),
       network_task_runner_(network_task_runner),

ios/web/shell/shell_url_request_context_getter.h

@@ -9,6 +9,7 @@
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/single_thread_task_runner.h"
 #include "net/url_request/url_request_context_getter.h"
 
@@ -31,7 +32,7 @@ class ShellURLRequestContextGetter : public net::URLRequestContextGetter {
       const base::FilePath& base_path,
       const scoped_refptr<base::SingleThreadTaskRunner>& network_task_runner,
       const scoped_refptr<base::SingleThreadTaskRunner>& file_task_runner,
-      const scoped_refptr<base::SingleThreadTaskRunner>& cache_task_runner);
+      const scoped_refptr<base::MessageLoopProxy>& cache_task_runner);
 
   // net::URLRequestContextGetter implementation.
   net::URLRequestContext* GetURLRequestContext() override;
@@ -45,7 +46,7 @@ class ShellURLRequestContextGetter : public net::URLRequestContextGetter {
   base::FilePath base_path_;
   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
-  scoped_refptr<base::SingleThreadTaskRunner> cache_task_runner_;
+  scoped_refptr<base::MessageLoopProxy> cache_task_runner_;
   scoped_ptr<net::ProxyConfigService> proxy_config_service_;
   scoped_ptr<net::NetworkDelegate> network_delegate_;
   scoped_ptr<net::URLRequestContextStorage> storage_;

ios/web/web_thread_adapter.cc

@@ -164,9 +164,9 @@ bool WebThread::GetCurrentThreadIdentifier(ID* identifier) {
 }
 
 // static
-scoped_refptr<base::SingleThreadTaskRunner> WebThread::GetTaskRunnerForThread(
+scoped_refptr<base::MessageLoopProxy> WebThread::GetMessageLoopProxyForThread(
     ID identifier) {
-  return content::BrowserThread::GetTaskRunnerForThread(
+  return content::BrowserThread::GetMessageLoopProxyForThread(
       BrowserThreadIDFromWebThreadID(identifier));
 }
 

ios/web/web_thread_impl.cc

@@ -11,7 +11,7 @@
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop.h"
-#include "base/single_thread_task_runner.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "ios/web/public/web_thread_delegate.h"
@@ -32,13 +32,14 @@ const char* g_web_thread_names[WebThread::ID_COUNT] = {
     "Web_IOThread",                // IO
 };
 
-// An implementation of SingleThreadTaskRunner to be used in conjunction
+// An implementation of MessageLoopProxy to be used in conjunction
 // with WebThread.
-class WebThreadTaskRunner : public base::SingleThreadTaskRunner {
+class WebThreadMessageLoopProxy : public base::MessageLoopProxy {
  public:
-  explicit WebThreadTaskRunner(WebThread::ID identifier) : id_(identifier) {}
+  explicit WebThreadMessageLoopProxy(WebThread::ID identifier)
+      : id_(identifier) {}
 
-  // SingleThreadTaskRunner implementation.
+  // MessageLoopProxy implementation.
   bool PostDelayedTask(const tracked_objects::Location& from_here,
                        const base::Closure& task,
                        base::TimeDelta delay) override {
@@ -56,26 +57,26 @@ class WebThreadTaskRunner : public base::SingleThreadTaskRunner {
   }
 
  protected:
-  ~WebThreadTaskRunner() override {}
+  ~WebThreadMessageLoopProxy() override {}
 
  private:
   WebThread::ID id_;
-  DISALLOW_COPY_AND_ASSIGN(WebThreadTaskRunner);
+  DISALLOW_COPY_AND_ASSIGN(WebThreadMessageLoopProxy);
 };
 
-// A separate helper is used just for the task runners, in order to avoid
-// needing to initialize the globals to create a task runner.
-struct WebThreadTaskRunners {
-  WebThreadTaskRunners() {
+// A separate helper is used just for the proxies, in order to avoid needing
+// to initialize the globals to create a proxy.
+struct WebThreadProxies {
+  WebThreadProxies() {
     for (int i = 0; i < WebThread::ID_COUNT; ++i) {
-      task_runners[i] = new WebThreadTaskRunner(static_cast<WebThread::ID>(i));
+      proxies[i] = new WebThreadMessageLoopProxy(static_cast<WebThread::ID>(i));
     }
   }
 
-  scoped_refptr<base::SingleThreadTaskRunner> task_runners[WebThread::ID_COUNT];
+  scoped_refptr<base::MessageLoopProxy> proxies[WebThread::ID_COUNT];
 };
 
-base::LazyInstance<WebThreadTaskRunners>::Leaky g_task_runners =
+base::LazyInstance<WebThreadProxies>::Leaky g_proxies =
     LAZY_INSTANCE_INITIALIZER;
 
 struct WebThreadGlobals {
@@ -450,7 +451,7 @@ bool WebThread::PostTaskAndReply(ID identifier,
                                  const tracked_objects::Location& from_here,
                                  const base::Closure& task,
                                  const base::Closure& reply) {
-  return GetTaskRunnerForThread(identifier)
+  return GetMessageLoopProxyForThread(identifier)
       ->PostTaskAndReply(from_here, task, reply);
 }
 
@@ -478,9 +479,9 @@ bool WebThread::GetCurrentThreadIdentifier(ID* identifier) {
 }
 
 // static
-scoped_refptr<base::SingleThreadTaskRunner> WebThread::GetTaskRunnerForThread(
+scoped_refptr<base::MessageLoopProxy> WebThread::GetMessageLoopProxyForThread(
     ID identifier) {
-  return g_task_runners.Get().task_runners[identifier];
+  return g_proxies.Get().proxies[identifier];
 }
 
 // static