Move prefix_set and parts of safe_browsing_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..4147fe9b59ff8cb1b75138856727c6e35a67367b
--- /dev/null
+++ b/components/safe_browsing_db/BUILD.gn
@@ -0,0 +1,49 @@
+# 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.
+
+group("safe_browsing_db") {
+  deps = [
+    ":prefix_set",
+    ":safe_browsing_db_util",
+  ]
+}
+
+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",
+    "//crypto",
+  ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "prefix_set_unittest.cc",
+    "safe_browsing_db_util_unittest.cc",
+  ]
+  deps = [
+    ":prefix_set",
+    ":safe_browsing_db_util",
+    "//base",
+    "//testing/gtest",
+  ]
+  if (is_win) {
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    cflags = [ "/wd4267" ]  # Conversion from size_t to 'type'.
+  }
+}