Disable compositing asserts when gesture scrolling on main thread

third_party/WebKit/Source/core/input/ScrollManager.cpp

Index: third_party/WebKit/Source/core/input/ScrollManager.cpp
diff --git a/third_party/WebKit/Source/core/input/ScrollManager.cpp b/third_party/WebKit/Source/core/input/ScrollManager.cpp
index 4ca799892a2a219453212646642ccb51d029d110..79ed36367d3acdb786c433e50add62597409bed7 100644
--- a/third_party/WebKit/Source/core/input/ScrollManager.cpp
+++ b/third_party/WebKit/Source/core/input/ScrollManager.cpp
@@ -194,10 +194,6 @@ WebInputEventResult ScrollManager::handleGestureScrollBegin(const PlatformGestur
     if (document->layoutViewItem().isNull())
         return WebInputEventResult::NotHandled;
 
-    FrameView* view = m_frame->view();
-    if (!view)
-        return WebInputEventResult::NotHandled;
-
     // If there's no layoutObject on the node, send the event to the nearest ancestor with a layoutObject.
     // Needed for <option> and <optgroup> elements so we can touch scroll <select>s
     while (m_scrollGestureHandlingNode && !m_scrollGestureHandlingNode->layoutObject())
@@ -356,6 +352,9 @@ bool ScrollManager::isEffectiveRootScroller(const Node& node) const
 
 WebInputEventResult ScrollManager::handleGestureScrollEvent(const PlatformGestureEvent& gestureEvent)
 {
+    if (!m_frame->view())
+        return WebInputEventResult::NotHandled;
+
     Node* eventTarget = nullptr;
     Scrollbar* scrollbar = nullptr;
     if (gestureEvent.type() != PlatformEvent::GestureScrollBegin) {