Move prefix_set and parts of s_b_util into a new component safe_browsing_db.

components/safe_browsing_db/BUILD.gn

Index: components/safe_browsing_db/BUILD.gn
diff --git a/components/safe_browsing_db/BUILD.gn b/components/safe_browsing_db/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..249557c6c3a8bd182ff42679bfa67f45f383a7f3
--- /dev/null
+++ b/components/safe_browsing_db/BUILD.gn
@@ -0,0 +1,47 @@
+# Copyright 2015 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("prefix_set") {
+  sources = [
+    "prefix_set.cc",
+    "prefix_set.h",
+  ]
+  deps = [
+    "//base",
+  ]
+}
+
+source_set("safe_browsing_db_util") {
+  sources = [
+    "safe_browsing_db_util.cc",
+    "safe_browsing_db_util.h",
+  ]
+  deps = [
+    "//base",
+  ]
+}
+
+source_set("prefix_set_unit_tests") {
+  testonly = true
+  sources = [
+    "prefix_set_unittest.cc",
+  ]
+  deps = [
+    ":prefix_set",
+    "//base",
+    "//testing/gtest",
+  ]
+}
+
+source_set("safe_browsing_db_util_unit_tests") {
+  testonly = true
+  sources = [
+    "safe_browsing_db_util_unittest.cc",
+  ]
+  deps = [
+    ":safe_browsing_db_util",
+    "//base",
+    "//testing/gtest",
+  ]
+}