Move overscroll logic out of EventHandler.

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 19 matching lines @@
 
 #include "core/frame/FrameHost.h"
 
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/PageScaleConstraints.h"
 #include "core/frame/PageScaleConstraintsSet.h"
 #include "core/frame/TopControls.h"
 #include "core/inspector/ConsoleMessageStorage.h"
 #include "core/page/Page.h"
+#include "core/page/scrolling/OverscrollController.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScheduler.h"
 
 namespace blink {
 
 FrameHost* FrameHost::create(Page& page)
 {
     return new FrameHost(page);
 }
 
 FrameHost::FrameHost(Page& page)
     : m_page(&page)
     , m_topControls(TopControls::create(*this))
     , m_pageScaleConstraintsSet(PageScaleConstraintsSet::create())
     , m_visualViewport(VisualViewport::create(*this))
+    , m_overscrollController(OverscrollController::create(
+        *m_visualViewport,
+        m_page->chromeClient()))
     , m_eventHandlerRegistry(new EventHandlerRegistry(*this))
     , m_consoleMessageStorage(ConsoleMessageStorage::create())
     , m_subframeCount(0)
 {
 }
 
 // Explicitly in the .cpp to avoid default constructor in .h
 FrameHost::~FrameHost()
 {
 }
@@ skipping 21 matching lines @@
 float FrameHost::deviceScaleFactor() const
 {
     return m_page->deviceScaleFactor();
 }
 
 TopControls& FrameHost::topControls() const
 {
     return *m_topControls;
 }
 
+OverscrollController& FrameHost::overscrollController() const

[dtapuska, 2016/04/26 13:53:11]

I got shamed for this last week and was explicitly told:
https://google.github.io/styleguide/cppguide.html#Use_of_const

explicitly; 'do not return non-const reference to a data member'

Now looking at again the interpretation is a little weird; but I'd assume you
could remove the const from the method definition and it would be fine.

Context:
https://codereview.chromium.org/1888163003/diff/100001/content/renderer/rende...

But I agree this matches what other methods are doing here as well so at least
it is consistently not following the guidance.

[bokan, 2016/04/26 16:09:53]

Yah, I was just being consistent but it's true that this isn't const-correct. In
general, lots of Blink code isn't const-correct and writing new code is made
more difficult because of this. I've added const and non-const overloads for
each method in this class to buck the trend.

+{
+    return *m_overscrollController;
+}
+
 VisualViewport& FrameHost::visualViewport() const
 {
     return *m_visualViewport;
 }
 
 PageScaleConstraintsSet& FrameHost::pageScaleConstraintsSet() const
 {
     return *m_pageScaleConstraintsSet;
 }
 
 EventHandlerRegistry& FrameHost::eventHandlerRegistry() const
 {
     return *m_eventHandlerRegistry;
 }
 
 ConsoleMessageStorage& FrameHost::consoleMessageStorage() const
 {
     return *m_consoleMessageStorage;
 }
 
 DEFINE_TRACE(FrameHost)
 {
     visitor->trace(m_page);
     visitor->trace(m_topControls);
     visitor->trace(m_visualViewport);
+    visitor->trace(m_overscrollController);
     visitor->trace(m_eventHandlerRegistry);
     visitor->trace(m_consoleMessageStorage);
 }
 
 #if ENABLE(ASSERT)
 void checkFrameCountConsistency(int expectedFrameCount, Frame* frame)
 {
     ASSERT(expectedFrameCount >= 0);
 
     int actualFrameCount = 0;
@@ skipping 48 matching lines @@
 
     FrameView* rootView = page().deprecatedLocalMainFrame()->view();
 
     if (!rootView)
         return;
 
     rootView->setNeedsLayout();
 }
 
 } // namespace blink