Move MessagePump::Type to its own type and file

MessagePumpType is used in other places (eg base/thread.h). Moving it to
its own file will simplify include dependencies.

Bug: 891670
Change-Id: I214342da0d6833e0ad324cd4d58c08a0233f7c1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1718806
Commit-Queue: Carlos Caballero <carlscab@google.com>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682235}

base/BUILD.gn

@@ -473,6 +473,7 @@ jumbo_component("base") {
     "message_loop/message_pump_io_ios.h",
     "message_loop/message_pump_mac.h",
     "message_loop/message_pump_mac.mm",
+    "message_loop/message_pump_type.h",
     "message_loop/message_pump_win.cc",
     "message_loop/message_pump_win.h",
     "message_loop/timer_slack.h",

base/message_loop/message_loop.h

@@ -14,7 +14,7 @@
 #include "base/macros.h"
 #include "base/memory/scoped_refptr.h"
 #include "base/message_loop/message_loop_current.h"
-#include "base/message_loop/message_pump.h"
+#include "base/message_loop/message_pump_type.h"
 #include "base/message_loop/timer_slack.h"
 #include "base/pending_task.h"
 #include "base/run_loop.h"
@@ -29,6 +29,7 @@ class MessageLoopTaskEnvironment;
 }  // namespace internal
 
 class MessageLoopImpl;
+class MessagePump;
 
 namespace sequence_manager {
 class TaskQueue;

base/message_loop/message_pump.cc

@@ -39,9 +39,9 @@ bool MessagePump::IsMessagePumpForUIFactoryOveridden() {
 }
 
 // static
-std::unique_ptr<MessagePump> MessagePump::Create(Type type) {
+std::unique_ptr<MessagePump> MessagePump::Create(MessagePumpType type) {
   switch (type) {
-    case Type::UI:
+    case MessagePumpType::UI:
       if (message_pump_for_ui_factory_)
         return message_pump_for_ui_factory_();
 #if defined(OS_IOS) || defined(OS_MACOSX)
@@ -55,32 +55,32 @@ std::unique_ptr<MessagePump> MessagePump::Create(Type type) {
       return std::make_unique<MessagePumpForUI>();
 #endif
 
-    case Type::IO:
+    case MessagePumpType::IO:
       return std::make_unique<MessagePumpForIO>();
 
 #if defined(OS_ANDROID)
-    case Type::JAVA:
+    case MessagePumpType::JAVA:
       return std::make_unique<MessagePumpForUI>();
 #endif
 
 #if defined(OS_MACOSX)
-    case Type::NS_RUNLOOP:
+    case MessagePumpType::NS_RUNLOOP:
       return std::make_unique<MessagePumpNSRunLoop>();
 #endif
 
 #if defined(OS_WIN)
-    case Type::UI_WITH_WM_QUIT_SUPPORT: {
+    case MessagePumpType::UI_WITH_WM_QUIT_SUPPORT: {
       auto pump = std::make_unique<MessagePumpForUI>();
       pump->EnableWmQuit();
       return pump;
     }
 #endif  // defined(OS_WIN)
 
-    case Type::CUSTOM:
+    case MessagePumpType::CUSTOM:
       NOTREACHED();
       return nullptr;
 
-    case Type::DEFAULT:
+    case MessagePumpType::DEFAULT:
 #if defined(OS_IOS)
       // On iOS, a native runloop is always required to pump system work.
       return std::make_unique<MessagePumpCFRunLoop>();

base/message_loop/message_pump.h

@@ -7,6 +7,7 @@
 
 #include "base/base_export.h"
 #include "base/logging.h"
+#include "base/message_loop/message_pump_type.h"
 #include "base/message_loop/timer_slack.h"
 #include "base/sequence_checker.h"
 #include "base/time/time.h"
@@ -18,47 +19,8 @@ class TimeTicks;
 
 class BASE_EXPORT MessagePump {
  public:
-  // A MessagePump has a particular type, which indicates the set of
-  // asynchronous events it may process in addition to tasks and timers.
-  //
-  // TYPE_DEFAULT
-  //   This type of pump only supports tasks and timers.
-  //
-  // TYPE_UI
-  //   This type of pump also supports native UI events (e.g., Windows
-  //   messages).
-  //
-  // TYPE_IO
-  //   This type of pump also supports asynchronous IO.
-  //
-  // TYPE_JAVA
-  //   This type of pump is backed by a Java message handler which is
-  //   responsible for running the tasks added to the ML. This is only for use
-  //   on Android. TYPE_JAVA behaves in essence like TYPE_UI, except during
-  //   construction where it does not use the main thread specific pump factory.
-  //
-  // TYPE_NS_RUNLOOP
-  //   This type of pump is backed by a NSRunLoop. This is only for use on
-  //   OSX and IOS.
-  //
-  // UI_WITH_WM_QUIT_SUPPORT
-  //   This type of pump supports WM_QUIT messages in addition to other native
-  //   UI events. This is only for use on windows.
-  enum class Type {
-    DEFAULT,
-    UI,
-    CUSTOM,
-    IO,
-#if defined(OS_ANDROID)
-    JAVA,
-#endif  // defined(OS_ANDROID)
-#if defined(OS_MACOSX)
-    NS_RUNLOOP,
-#endif  // defined(OS_MACOSX)
-#if defined(OS_WIN)
-    UI_WITH_WM_QUIT_SUPPORT,
-#endif  // defined(OS_WIN)
-  };
+  // DEPRECATED: Use MessagePumpType instead.
+  using Type = MessagePumpType;
 
   using MessagePumpFactory = std::unique_ptr<MessagePump>();
   // Uses the given base::MessagePumpFactory to override the default MessagePump
@@ -69,7 +31,7 @@ class BASE_EXPORT MessagePump {
   static bool IsMessagePumpForUIFactoryOveridden();
 
   // Creates the default MessagePump based on |type|. Caller owns return value.
-  static std::unique_ptr<MessagePump> Create(Type type);
+  static std::unique_ptr<MessagePump> Create(MessagePumpType type);
 
   // Please see the comments above the Run method for an illustration of how
   // these delegate methods are used.

base/message_loop/message_pump_type.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_TYPE_H_
+#define BASE_MESSAGE_LOOP_MESSAGE_PUMP_TYPE_H_
+
+#include "build/build_config.h"
+
+namespace base {
+
+// A MessagePump has a particular type, which indicates the set of
+// asynchronous events it may process in addition to tasks and timers.
+
+enum class MessagePumpType {
+  // This type of pump only supports tasks and timers.
+  DEFAULT,
+
+  // This type of pump also supports native UI events (e.g., Windows
+  // messages).
+  UI,
+
+  // User provided implementation of MessagePump interface
+  CUSTOM,
+
+  // This type of pump also supports asynchronous IO.
+  IO,
+
+#if defined(OS_ANDROID)
+  // This type of pump is backed by a Java message handler which is
+  // responsible for running the tasks added to the ML. This is only for use
+  // on Android. TYPE_JAVA behaves in essence like TYPE_UI, except during
+  // construction where it does not use the main thread specific pump factory.
+  JAVA,
+#endif  // defined(OS_ANDROID)
+
+#if defined(OS_MACOSX)
+  // This type of pump is backed by a NSRunLoop. This is only for use on
+  // OSX and IOS.
+  NS_RUNLOOP,
+#endif  // defined(OS_MACOSX)
+
+#if defined(OS_WIN)
+  // This type of pump supports WM_QUIT messages in addition to other native
+  // UI events. This is only for use on windows.
+  UI_WITH_WM_QUIT_SUPPORT,
+#endif  // defined(OS_WIN)
+};
+
+}  // namespace base
+
+#endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_TYPE_H_