Make net_unittests_run work with component=shared_library.

base/base_prefs.isolate

Index: base/base_prefs.isolate
diff --git a/base/base_prefs.isolate b/base/base_prefs.isolate
new file mode 100644
index 0000000000000000000000000000000000000000..dbc94d3d77c43f4034a4b8c176fbbc57ab7bf58a
--- /dev/null
+++ b/base/base_prefs.isolate
@@ -0,0 +1,28 @@
+# 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.
+{
+  'conditions': [
+    ['OS=="linux" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/lib/libbase_prefs.so',
+        ],
+      },
+    }],
+    ['OS=="mac" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/libbase_prefs.dylib',
+        ],
+      },
+    }],
+    ['OS=="win" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/base_prefs.dll',
+        ],
+      },
+    }],
+  ],
+}