Add support for component=shared_library for base_unittests_run.

base/base.isolate

+# Copyright (c) 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.so',
+          '<(PRODUCT_DIR)/lib/libbase_i18n.so',
+          '<(PRODUCT_DIR)/lib/libbase_prefs.so',
+        ],
+      },
+    }],
+    ['OS=="mac" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/libbase.dylib',
+          '<(PRODUCT_DIR)/libbase_i18n.dylib',
+          '<(PRODUCT_DIR)/libbase_prefs.dylib',
+        ],
+      },
+    }],
+    ['OS=="win" and component=="shared_library"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/base.dll',
+          '<(PRODUCT_DIR)/base_i18n.dll',
+          '<(PRODUCT_DIR)/base_prefs.dll',
+        ],
+      },
+    }],
+  ],
+  'includes': [
+    '../build/linux/system.isolate',
+    '../third_party/icu/icu.isolate',
+  ],
+}