Revert of scheduler: Re-enable timer throttling for hidden frames (pa…

…tchset #6 id:100001 of https://codereview.chromium.org/2468863002/ )

Reason for revert:
Regressed crbug.com/647393.

Original issue's description:
> scheduler: Re-enable timer throttling for hidden frames
>
> Turn hidden timer throttling back now that the issue with Gmail pop-ups
> not working has been resolved by https://codereview.chromium.org/2272773002/.
>
> This patch also fixes a timer throttling related rebase error in a
> previous patch and adds new layout test that cover out-of-view timer
> and requestAnimationFrame throttling.
>
> Intent to ship: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/_Lhz8THHk2Q
>
> BUG=616519,647393
>
> Committed: https://crrev.com/1688130897aed95d32e3904a6aa10384414fbefe
> Cr-Commit-Position: refs/heads/master@{#432642}

TBR=kinuko@chromium.org,ojan@chromium.org,ojan@google.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=616519,647393

Review-Url: https://codereview.chromium.org/2511283002
Cr-Commit-Position: refs/heads/master@{#433061}

content/public/common/content_features.cc

@@ -199,7 +199,7 @@ const base::Feature kStaleWhileRevalidate{"StaleWhileRevalidate2",
 
 // Throttle Blink timers in out-of-view cross origin frames.
 const base::Feature kTimerThrottlingForHiddenFrames{
-    "TimerThrottlingForHiddenFrames", base::FEATURE_ENABLED_BY_DEFAULT};
+    "TimerThrottlingForHiddenFrames", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables token binding
 // (https://www.ietf.org/id/draft-ietf-tokbind-protocol-04.txt).

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js

@@ -51,9 +51,6 @@ function with_iframe(url, options) {
   return new Promise(function(resolve) {
       var frame = document.createElement('iframe');
       frame.src = url;
-      // Make sure the iframe stays in the viewport even if the test creates
-      // many of them. Otherwise some iframes may end up being throttled.
-      frame.style.position = 'absolute';
       frame.onload = function() { resolve(frame); };
       document.body.appendChild(frame);
       if (typeof options === 'undefined')

third_party/WebKit/Source/core/frame/FrameView.cpp

@@ -4522,11 +4522,6 @@ void FrameView::updateRenderThrottlingStatus(bool hidden,
       hasHandlers)
     scrollingCoordinator->touchEventTargetRectsDidChange();
 
-  if (m_frame->frameScheduler()) {
-    m_frame->frameScheduler()->setFrameVisible(!m_hiddenForThrottling);
-    m_frame->frameScheduler()->setCrossOrigin(m_frame->isCrossOriginSubframe());
-  }
-
 #if DCHECK_IS_ON()
   // Make sure we never have an unthrottled frame inside a throttled one.
   FrameView* parent = parentFrameView();