Move storage tests from content/common next to the files they cover.

storage/common/BUILD.gn

 # Copyright 2014 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.
 
 component("common") {
   output_name = "storage_common"
   sources = [
     "blob_storage/blob_item_bytes_request.cc",
     "blob_storage/blob_item_bytes_request.h",
     "blob_storage/blob_item_bytes_response.cc",
@@ skipping 29 matching lines @@
   defines = [ "STORAGE_COMMON_IMPLEMENTATION" ]
 
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
     "//net",
     "//third_party/WebKit/public:blink_headers",
     "//url",
   ]
 }
+
+source_set("unittests") {
+  testonly = true
+
+  sources = [
+    "database/database_connections_unittest.cc",
+    "database/database_identifier_unittest.cc",
+    "fileapi/file_system_util_unittest.cc",
+  ]
+
+  deps = [
+    ":common",
+    "//base/test:run_all_unittests",
+    "//base/test:test_support",
+    "//testing/gtest",
+    "//url",
+  ]
+}