IntersectionObserver: second cut.

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

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index f0b373487b502c3973dbca8ac8075b92b10eb91b..c0431a9a763e1b044e25aadb0514b1bc0dcf8d20 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -75,6 +75,7 @@
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/FrameRequestCallback.h"
+#include "core/dom/IntersectionObserverController.h"
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 #include "core/dom/MainThreadTaskRunner.h"
 #include "core/dom/Microtask.h"
@@ -608,6 +609,11 @@ void Document::dispose()
     if (svgExtensions())
         accessSVGExtensions().pauseAnimations();
 
+    if (m_intersectionObserverController) {
+        m_intersectionObserverController->dispose();
+        m_intersectionObserverController.clear();
+    }

[haraken, 2015/12/22 01:13:29]

I think we should call these in Document::detach, not Document::dispose.
Remember that Document::dispose is not called in oilpan.

[szager1, 2015/12/22 07:53:40]

In oilpan, it should not be necessary to run this code.  Even without oilpan,
this code is mostly defensive: I want to make sure that
m_intersectionObserverController does not prevent any IntersectionObservers from
being garbage collected on the next gc run.

+
     m_lifecycle.advanceTo(DocumentLifecycle::Disposed);
     DocumentLifecycleNotifier::notifyDocumentWasDisposed();
 
@@ -4579,11 +4585,7 @@ WeakPtrWillBeRawPtr<Document> Document::contextDocument()
     if (m_contextDocument)
         return m_contextDocument;
     if (m_frame) {
-#if ENABLE(OILPAN)
-        return this;
-#else
-        return m_weakFactory.createWeakPtr();
-#endif
+        return createWeakPtr();
     }
     return nullptr;
 }
@@ -5059,6 +5061,22 @@ void Document::parseDNSPrefetchControlHeader(const String& dnsPrefetchControl)
     m_haveExplicitlyDisabledDNSPrefetch = true;
 }
 
+WeakPtrWillBeRawPtr<Document> Document::createWeakPtr()
+{
+#if ENABLE(OILPAN)
+    return this;
+#else
+    return m_weakFactory.createWeakPtr();
+#endif
+}
+
+IntersectionObserverController& Document::intersectionObserverController()

[haraken, 2015/12/22 01:13:29]

intersectionObserverController() => ensureIntersectionObserverController()

[szager1, 2015/12/22 07:53:40]

Done.

+{
+    if (!m_intersectionObserverController)
+        m_intersectionObserverController = new IntersectionObserverController();
+    return *m_intersectionObserverController;
+}
+
 void Document::reportBlockedScriptExecutionToInspector(const String& directiveText)
 {
     InspectorInstrumentation::scriptExecutionBlockedByCSP(this, directiveText);
@@ -5116,6 +5134,8 @@ void Document::tasksWereResumed()
         m_scriptedAnimationController->resume();
 
     MutationObserver::resumeSuspendedObservers();
+    if (m_intersectionObserverController)
+        m_intersectionObserverController->resumeSuspendedIntersectionObservers();
     if (m_domWindow)
         DOMWindowPerformance::performance(*m_domWindow)->resumeSuspendedObservers();
 }
@@ -5862,6 +5882,7 @@ DEFINE_TRACE(Document)
     visitor->trace(m_compositorPendingAnimations);
     visitor->trace(m_contextDocument);
     visitor->trace(m_canvasFontCache);
+    visitor->trace(m_intersectionObserverController);
     WillBeHeapSupplementable<Document>::trace(visitor);
 #endif
     TreeScope::trace(visitor);