Refactor IntersectionGeometry class and move it to core/layout.

third_party/WebKit/Source/core/dom/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//third_party/WebKit/Source/core/core.gni")
 
 blink_core_sources("dom") {
   split_count = 5
 
   sources = [
@@ skipping 137 matching lines @@
     "IdTargetObserver.cpp",
     "IdTargetObserver.h",
     "IdTargetObserverRegistry.cpp",
     "IdTargetObserverRegistry.h",
     "IdleDeadline.cpp",
     "IdleDeadline.h",
     "IdleRequestCallback.h",
     "IgnoreDestructiveWriteCountIncrementer.h",
     "IncrementLoadEventDelayCount.cpp",
     "IncrementLoadEventDelayCount.h",
-    "IntersectionGeometry.cpp",
-    "IntersectionGeometry.h",
     "IntersectionObservation.cpp",
     "IntersectionObservation.h",
     "IntersectionObserver.cpp",
     "IntersectionObserver.h",
     "IntersectionObserverController.cpp",
     "IntersectionObserverController.h",
     "IntersectionObserverEntry.cpp",
     "IntersectionObserverEntry.h",
     "Iterator.h",
     "LayoutTreeBuilder.cpp",
@@ skipping 222 matching lines @@
     "shadow/SlotAssignment.h",
     "shadow/SlotScopedTraversal.cpp",
     "shadow/SlotScopedTraversal.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 }