Create component to expose network usage stats to consumers.

components/data_usage/core/BUILD.gn

Index: components/data_usage/core/BUILD.gn
diff --git a/components/certificate_transparency/BUILD.gn b/components/data_usage/core/BUILD.gn
similarity index 57%
copy from components/certificate_transparency/BUILD.gn
copy to components/data_usage/core/BUILD.gn
index c541f9763306edb98a1fe54f338102cb83d5f777..963e9e95483232762bd0eec3080d2fc2a21c4142 100644
--- a/components/certificate_transparency/BUILD.gn
+++ b/components/data_usage/core/BUILD.gn
@@ -2,15 +2,15 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("certificate_transparency") {
+source_set("core") {
   sources = [
-    "log_proof_fetcher.cc",
-    "log_proof_fetcher.h",
+    "data_use.cc",
+    "data_use.h",
+    "data_use_aggregator.cc",
+    "data_use_aggregator.h",
   ]
-
   deps = [
     "//base",
-    "//components/safe_json",
     "//net",
     "//url",
   ]
@@ -19,12 +19,16 @@ source_set("certificate_transparency") {
 source_set("unit_tests") {
   testonly = true
   sources = [
-    "log_proof_fetcher_unittest.cc",
+    "data_use_aggregator_unittest.cc",
   ]
 
+  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
+
   deps = [
-    ":certificate_transparency",
+    ":core",
+    "//base",
     "//base/test:test_support",
+    "//net:test_support",
     "//testing/gtest",
   ]
 }