[scheduler] Move some task types to suspendable task runner.

third_party/WebKit/Source/core/dom/TaskRunnerHelper.cpp

 // Copyright 2016 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.
 
 #include "core/dom/TaskRunnerHelper.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/LocalFrame.h"
 #include "platform/WebFrameScheduler.h"
 #include "platform/WebTaskRunner.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebThread.h"
 
 namespace blink {
 
 RefPtr<WebTaskRunner> TaskRunnerHelper::Get(TaskType type, LocalFrame* frame) {
   // TODO(haraken): Optimize the mapping from TaskTypes to task runners.
   switch (type) {
     case TaskType::kTimer:
       return frame ? frame->FrameScheduler()->TimerTaskRunner()
                    : Platform::Current()->CurrentThread()->GetWebTaskRunner();
     case TaskType::kUnspecedLoading:
     case TaskType::kNetworking:
       return frame ? frame->FrameScheduler()->LoadingTaskRunner()
                    : Platform::Current()->CurrentThread()->GetWebTaskRunner();
     // Throttling following tasks may break existing web pages, so tentatively
     // these are unthrottled.
     // TODO(nhiroki): Throttle them again after we're convinced that it's safe

[Sami, 2017/04/12 15:24:50]

Does this comment need updating by the way?

     // or provide a mechanism that web pages can opt-out it if throttling is not
     // desirable.
+    case TaskType::kDOMManipulation:
     case TaskType::kDatabaseAccess:
+    case TaskType::kFileReading:
+    case TaskType::kHistoryTraversal:
+    case TaskType::kPerformanceTimeline:
+    case TaskType::kPostedMessage:
+    case TaskType::kRemoteEvent:
+    case TaskType::kSensor:
+    case TaskType::kUnshippedPortMessage:
+    case TaskType::kWebSocket:
       return frame ? frame->FrameScheduler()->SuspendableTaskRunner()
                    : Platform::Current()->CurrentThread()->GetWebTaskRunner();
-    case TaskType::kDOMManipulation:
     case TaskType::kUserInteraction:
-    case TaskType::kHistoryTraversal:
     case TaskType::kEmbed:
     case TaskType::kMediaElementEvent:
     case TaskType::kCanvasBlobSerialization:
-    case TaskType::kRemoteEvent:
-    case TaskType::kWebSocket:
     case TaskType::kMicrotask:
-    case TaskType::kPostedMessage:
-    case TaskType::kUnshippedPortMessage:
-    case TaskType::kFileReading:
     case TaskType::kPresentation:
-    case TaskType::kSensor:
-    case TaskType::kPerformanceTimeline:
     case TaskType::kWebGL:
     case TaskType::kUnspecedTimer:
     case TaskType::kMiscPlatformAPI:
     case TaskType::kUnthrottled:
       return frame ? frame->FrameScheduler()->UnthrottledTaskRunner()
                    : Platform::Current()->CurrentThread()->GetWebTaskRunner();
   }
   NOTREACHED();
   return nullptr;
 }
@@ skipping 10 matching lines @@
                        : nullptr);
 }
 
 RefPtr<WebTaskRunner> TaskRunnerHelper::Get(TaskType type,
                                             ScriptState* script_state) {
   return Get(type,
              script_state ? script_state->GetExecutionContext() : nullptr);
 }
 
 }  // namespace blink