ResizeObserver pt6: integration

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

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 4784dd7466c71d63bfc859a221047804fdb73f04..7515b37b48ab0c50e5ef2ef92a2587b529fa3485 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -38,6 +38,7 @@
 #include "core/editing/FrameSelection.h"
 #include "core/editing/RenderedPosition.h"
 #include "core/editing/markers/DocumentMarkerController.h"
+#include "core/events/ErrorEvent.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameHost.h"
@@ -75,6 +76,7 @@
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
+#include "core/observer/ResizeObserverController.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusController.h"
@@ -2515,6 +2517,36 @@ void FrameView::scheduleVisualUpdateForPaintInvalidationIfNeeded()
     // Otherwise the paint invalidation will be handled in paint invalidation phase of this cycle.
 }
 
+void FrameView::notifyResizeObserver()

[esprehn, 2016/08/10 04:27:09]

Observers() I think you want plural?

[atotic1, 2016/08/10 18:25:33]

Done.

I usually keep everything singular for simplicity.

+{
+    // Controller exists only if ResizeObserver was created.
+    if (!frame().document()->resizeObserverController())
+        return;
+
+    ResizeObserverController& resizeController = m_frame->document()->ensureResizeObserverController();
+
+    DCHECK(lifecycle().state() >= DocumentLifecycle::LayoutClean);
+
+    size_t minDepth = 0;
+    for (minDepth = resizeController.gatherObservations(0);
+        minDepth != ResizeObserverController::kDepthBottom;
+        minDepth = resizeController.gatherObservations(minDepth)) {
+        resizeController.deliverObservations();
+        frame().document()->updateStyleAndLayout();
+    }
+
+    if (resizeController.skippedObservations()) {
+        resizeController.clearObservations();

[esprehn, 2016/08/10 04:27:09]

Hmm, if we clear the observations how does scheduling a frame below go about
calling all of the observers again?

[atotic1, 2016/08/10 18:25:33]

This is non-obvious.

ResizeObserver has a set of active observations.
gather/deliver/clear/skipped API operates on this set.

ResizeObserverController/ResizeObserver/ResizeObservation have "changed" flags. 

Active observations are regenerated for every event loop from a set of 
"changed" flags.

"changed" flags are only cleared when observations on deliver(), not on clear().

+        ErrorEvent * error = ErrorEvent::create("ResizeObserver loop limit exceeded", SourceLocation::capture(m_frame->document()), nullptr);
+        m_frame->document()->reportException(error, NotSharableCrossOrigin);
+        // Ensure notifications will get delivered in next cycle.
+        if (FrameView* frameView = m_frame->view())
+            frameView->scheduleAnimation();
+    }
+
+    DCHECK(!layoutView()->needsLayout());
+}
+
 // TODO(leviw): We don't assert lifecycle information from documents in child PluginViews.
 void FrameView::updateLifecyclePhasesInternal(DocumentLifecycle::LifecycleState targetState)
 {
@@ -2546,6 +2578,10 @@ void FrameView::updateLifecyclePhasesInternal(DocumentLifecycle::LifecycleState
         return;
     }
 
+    forAllNonThrottledFrameViews([](FrameView& frameView) {
+        frameView.notifyResizeObserver();

[esprehn, 2016/08/10 04:27:09]

Did you add some iframe tests where the new ResizeObserver call is inside the
iframe?

[atotic1, 2016/08/10 18:25:33]

observer.html, test6()

+    });
+
     if (LayoutViewItem view = layoutViewItem()) {
         forAllNonThrottledFrameViews([](FrameView& frameView) {
             frameView.checkDoesNotNeedLayout();