Move overscroll logic out of EventHandler.

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

Index: third_party/WebKit/Source/core/frame/FrameHost.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameHost.cpp b/third_party/WebKit/Source/core/frame/FrameHost.cpp
index 90c54b893a8ba43504bf11198526cde4df1a3fa6..e1c6c23bccc4ad0cd8e6334250d808b3decd842c 100644
--- a/third_party/WebKit/Source/core/frame/FrameHost.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameHost.cpp
@@ -37,6 +37,7 @@
 #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"
 
@@ -52,6 +53,9 @@ FrameHost::FrameHost(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)
@@ -93,6 +97,11 @@ 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;
@@ -118,6 +127,7 @@ 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);
 }