Move cc::DisplayItemList and related classes into cc/paint/

cc/debug/BUILD.gn

+# Copyright 2017 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("//cc/cc.gni")
+cc_component("debug") {
+  output_name = "cc_debug"
+  sources = [
+    "debug_colors.cc",
+    "debug_colors.h",
+    "debug_export.h",
+    "layer_tree_debug_state.cc",
+    "layer_tree_debug_state.h",
+    "picture_debug_util.cc",
+    "picture_debug_util.h",
+    "rendering_stats.cc",
+    "rendering_stats.h",
+    "rendering_stats_instrumentation.cc",
+    "rendering_stats_instrumentation.h",
+    "traced_value.cc",
+    "traced_value.h",
+  ]
+  deps = [
+    "//base",
+    "//skia",
+    "//ui/gfx/codec",
+  ]
+
+  defines = [ "CC_DEBUG_IMPLEMENTATION=1" ]
+}