Decompose //extensions/browser/BUILD.gn

extensions/browser/api/system_cpu/BUILD.gn

Index: extensions/browser/api/system_cpu/BUILD.gn
diff --git a/extensions/browser/api/system_cpu/BUILD.gn b/extensions/browser/api/system_cpu/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..4b20d66ac69b0d04587b3542c1713deb62421d94
--- /dev/null
+++ b/extensions/browser/api/system_cpu/BUILD.gn
@@ -0,0 +1,19 @@
+# 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.
+
+source_set("system_cpu") {
+  sources = [
+    "cpu_info_provider.cc",
+    "cpu_info_provider.h",
+    "cpu_info_provider_linux.cc",
+    "cpu_info_provider_mac.cc",
+    "cpu_info_provider_win.cc",
+    "system_cpu_api.cc",
+    "system_cpu_api.h",
+  ]
+
+  deps = [
+    "//extensions/common/api",
+  ]
+}