cc: Detach spiral iterator implementation to separate file.

cc/BUILD.gn

 # Copyright 2014 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("//build/config/ui.gni")
 import("//testing/test.gni")
 
 component("cc") {
   sources = [
     "animation/animation.cc",
@@ skipping 805 matching lines @@
     "base/float_quad_unittest.cc",
     "base/histograms_unittest.cc",
     "base/index_rect_unittest.cc",
     "base/list_container_unittest.cc",
     "base/math_util_unittest.cc",
     "base/random_access_list_container_unittest.cc",
     "base/region_unittest.cc",
     "base/rolling_time_delta_history_unittest.cc",
     "base/rtree_unittest.cc",
     "base/simple_enclosed_region_unittest.cc",
+    "base/spiral_iterator_unittest.cc",
     "base/tiling_data_unittest.cc",
     "base/unique_notifier_unittest.cc",
     "blimp/picture_data_conversions_unittest.cc",
     "debug/layer_tree_debug_state_unittest.cc",
     "debug/micro_benchmark_controller_unittest.cc",
     "debug/rendering_stats_unittest.cc",
     "input/layer_selection_bound_unittest.cc",
     "input/scroll_state_unittest.cc",
     "input/scrollbar_animation_controller_linear_fade_unittest.cc",
     "input/scrollbar_animation_controller_thinning_unittest.cc",
@@ skipping 218 matching lines @@
     "//ui/gl:test_support",
   ]
 
   # This target should not require the Chrome executable to run.
   assert_no_deps = [ "//chrome" ]
 
   data = [
     "test/data/",
   ]
 }