requestIdleCallback: Yield for high priority work

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 f35300d57e5c330cf16c747342813ead8df10a5f..d17f46c68f830a299ddaec13be3d663e8fd02bad 100644
--- a/third_party/WebKit/Source/core/dom/IdleDeadline.cpp
+++ b/third_party/WebKit/Source/core/dom/IdleDeadline.cpp
@@ -5,6 +5,8 @@
 #include "core/dom/IdleDeadline.h"
 
 #include "core/timing/PerformanceBase.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebScheduler.h"
 #include "wtf/CurrentTime.h"
 
 namespace blink {
@@ -14,8 +16,14 @@ IdleDeadline::IdleDeadline(double deadlineSeconds, CallbackType callbackType)
 
 double IdleDeadline::timeRemaining() const {
   double timeRemaining = m_deadlineSeconds - monotonicallyIncreasingTime();
-  if (timeRemaining < 0)
+  if (timeRemaining < 0) {
     timeRemaining = 0;

[esprehn, 2016/11/21 20:32:27]

Early return in blink.

if (timeRemaining < 0)
  return 0;

if (....)
  return 0;

return 1000.0 * PerformanceBase::clampTimeResolution(timeRemaining);

+  } else if (Platform::current()
+                 ->currentThread()
+                 ->scheduler()
+                 ->shouldYieldForHighPriorityWork()) {
+    timeRemaining = 0;
+  }
 
   return 1000.0 * PerformanceBase::clampTimeResolution(timeRemaining);
 }