The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/453e03e72d02fb698ba2eee8550245928a8ab3a5

commit 453e03e72d02fb698ba2eee8550245928a8ab3a5
Author: haraken <haraken@chromium.org>
Date: Wed Jul 13 03:15:50 2016

Add helper functions to get per-frame task runners

This CL introduces TaskRunnerHelper that collects helper functions to get task runners.

This CL removes code to look up task runners of m_importsController and m_contextDocument
(I don't think it's needed; we can just fall back to the default task runner
when document->frame() is not available).

BUG=624689

Review-Url: https://codereview.chromium.org/2141873002
Cr-Commit-Position: refs/heads/master@{#404946}

[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/core.gypi
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/Document.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/Document.h
[add] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/TaskRunnerHelper.cpp
[add] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/parser/HTMLScriptRunner.cpp

Now that we landed TaskRunnerHelper, our goal is to replace Platform::current()->currentThread(->scheduler())->... and timers with TaskRunnerHelper::getXXXTaskRunner().

We can start distributing the work :)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/453e03e72d02fb698ba2eee8550245928a8ab3a5

commit 453e03e72d02fb698ba2eee8550245928a8ab3a5
Author: haraken <haraken@chromium.org>
Date: Wed Jul 13 03:15:50 2016

Add helper functions to get per-frame task runners

This CL introduces TaskRunnerHelper that collects helper functions to get task runners.

This CL removes code to look up task runners of m_importsController and m_contextDocument
(I don't think it's needed; we can just fall back to the default task runner
when document->frame() is not available).

BUG=624689

Review-Url: https://codereview.chromium.org/2141873002
Cr-Commit-Position: refs/heads/master@{#404946}

[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/core.gypi
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/Document.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/Document.h
[add] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/TaskRunnerHelper.cpp
[add] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/parser/HTMLDocumentParser.cpp
[modify] https://crrev.com/453e03e72d02fb698ba2eee8550245928a8ab3a5/third_party/WebKit/Source/core/html/parser/HTMLScriptRunner.cpp

We discussed what tasks should use what task runners in https://groups.google.com/a/chromium.org/d/topic/platform-architecture-dev/uRvrk4CYSEc/discussion.

The conclusion is as follows:

- Per-frame scheduler
---- Idle task runner
---- Timer task runner
---- Loading task runner
---- Rendering task runner
---- ... (<= We may add more specific task runners as necessary.)
---- Unthrottled task runner (<= not encouraged)

- Per-thread scheduler
--- Idle task runner (<= not encouraged)
--- Default task runner (<= not encouraged)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/19b8ee3aff5d67dd49f83e98c65f2410a9d4cf62

commit 19b8ee3aff5d67dd49f83e98c65f2410a9d4cf62
Author: haraken <haraken@chromium.org>
Date: Fri Aug 05 03:29:50 2016

Introduce TaskRunnerHelper::get()

Per the discussion in https://groups.google.com/a/chromium.org/d/topic/platform-architecture-dev/uRvrk4CYSEc/discussion,
this CL introduces TaskRunnerHelper::get(), which maps TaskRunnerTypes
to actual task runners.

BUG=624689

Review-Url: https://codereview.chromium.org/2209023002
Cr-Commit-Position: refs/heads/master@{#409982}

[modify] https://crrev.com/19b8ee3aff5d67dd49f83e98c65f2410a9d4cf62/third_party/WebKit/Source/core/dom/TaskRunnerHelper.cpp
[modify] https://crrev.com/19b8ee3aff5d67dd49f83e98c65f2410a9d4cf62/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h

 Issue 560402  has been merged into this issue.