Move geometry interface files to geometry directory.

third_party/WebKit/Source/core/geometry/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("geometry") {
+  split_count = 5
+
+  sources = [
+    "DOMMatrix.cpp",
+    "DOMMatrix.h",
+    "DOMMatrixReadOnly.cpp",
+    "DOMMatrixReadOnly.h",
+    "DOMPoint.cpp",
+    "DOMPoint.h",
+    "DOMPointReadOnly.cpp",
+    "DOMPointReadOnly.h",
+    "DOMQuad.cpp",
+    "DOMQuad.h",
+    "DOMRect.cpp",
+    "DOMRect.h",
+    "DOMRectReadOnly.cpp",
+    "DOMRectReadOnly.h",
+  ]
+
+  configs += [
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+  ]
+}