Unreviewed, a bit conservative parameter for JetStream2

https://bugs.webkit.org/show_bug.cgi?id=265104
rdar://118615311

JetStream2 showed regression, so we use a bit conservative parameter which is already tested as JetStream2 neutral (but Speedometer3 becomes 0.6% progression instead of 0.9%).

* Source/WebCore/page/OpportunisticTaskScheduler.cpp:
(WebCore::OpportunisticTaskScheduler::FullGCActivityCallback::doCollection):
(WebCore::OpportunisticTaskScheduler::EdenGCActivityCallback::doCollection):

Canonical link: https://commits.webkit.org/270948@main

Source/WebCore/page/OpportunisticTaskScheduler.cpp

@@ -178,7 +178,7 @@ static bool isBusyForTimerBasedGC()
 void OpportunisticTaskScheduler::FullGCActivityCallback::doCollection(JSC::VM& vm)
 {
     constexpr Seconds delay { 100_ms };
-    constexpr unsigned deferCountThreshold = 5;
+    constexpr unsigned deferCountThreshold = 3;
 
     if (isBusyForTimerBasedGC()) {
         if (!m_version || m_version != vm.heap.objectSpace().markingVersion()) {
@@ -203,8 +203,8 @@ void OpportunisticTaskScheduler::FullGCActivityCallback::doCollection(JSC::VM& v
 
 void OpportunisticTaskScheduler::EdenGCActivityCallback::doCollection(JSC::VM& vm)
 {
-    constexpr Seconds delay { 20_ms };
-    constexpr unsigned deferCountThreshold = 3;
+    constexpr Seconds delay { 10_ms };
+    constexpr unsigned deferCountThreshold = 5;
 
     if (isBusyForTimerBasedGC()) {
         if (!m_version || m_version != vm.heap.objectSpace().edenVersion()) {