Clamp resolution of requestIdleCallback timeRemaining() to 5us.

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

Index: third_party/WebKit/Source/core/dom/IdleDeadline.cpp
diff --git a/third_party/WebKit/Source/core/dom/IdleDeadline.cpp b/third_party/WebKit/Source/core/dom/IdleDeadline.cpp
index ed7f04eb2d6dec18533ce8cd777009394d5044a9..13f30bd33dd7d6f910b5b643fa401b0e4e996999 100644
--- a/third_party/WebKit/Source/core/dom/IdleDeadline.cpp
+++ b/third_party/WebKit/Source/core/dom/IdleDeadline.cpp
@@ -21,7 +21,8 @@ double IdleDeadline::timeRemaining() const
     if (timeRemaining < 0)
         timeRemaining = 0;
 
-    return timeRemaining * 1000;
+    const double resolutionSeconds = 0.000005;

[esprehn, 2015/09/24 21:33:06]

This is just duplicating what performance.now does, can we just call whatever
that calls? All timers in the engine should probably clamp to this...

[rmcilroy, 2015/09/24 22:53:18]

Good idea, added PerformanceBase::clampTimeResolution for this (happy to move
this if you have a suggestion for a better location).
By this do you mean the likes of PerformanceTimer, PerformanceUserTiming,
ResourceTimingInfo, etc? Ilya: would this work from a spec point of view? If so
I can do this in a followup CL.

+    return 1000.0 * floor(timeRemaining / resolutionSeconds) * resolutionSeconds;
 }
 
 } // namespace blink