Get rid of all component builds specific .isolate.

base/base_prefs.isolate

Index: base/base_prefs.isolate
diff --git a/base/base_prefs.isolate b/base/base_prefs.isolate
deleted file mode 100644
index dbc94d3d77c43f4034a4b8c176fbbc57ab7bf58a..0000000000000000000000000000000000000000
--- a/base/base_prefs.isolate
+++ /dev/null
@@ -1,28 +0,0 @@
-# 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',
-        ],
-      },
-    }],
-  ],
-}