Fix libdl dependency on Android and remove librt hack.

tools/gyp/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 1375 matching lines @@
               '../../src/base/platform/platform-linux.cc',
               '../../src/base/platform/platform-posix.cc'
             ],
           }
         ],
         ['OS=="android"', {
             'sources': [
               '../../src/base/platform/platform-posix.cc'
             ],
             'link_settings': {
-              'libraries': [
-                '-ldl'
+              'target_conditions': [
+                ['_toolset=="host"', {
+                  # Only include libdl and librt on host builds because they
+                  # are included by default on Android target builds, and we
+                  # don't want to re-include them here since this will change
+                  # library order and break (see crbug.com/469973).
+                  'libraries': [
+                    '-ldl',
+                    '-lrt'
+                  ]
+                }]
               ]
             },
             'conditions': [
               ['host_os=="mac"', {
                 'target_conditions': [
                   ['_toolset=="host"', {
                     'sources': [
                       '../../src/base/platform/platform-macos.cc'
                     ]
                   }, {
                     'sources': [
                       '../../src/base/platform/platform-linux.cc'
                     ]
                   }],
                 ],
               }, {
-                # TODO(bmeurer): What we really want here, is this:
-                #
-                # 'link_settings': {
-                #   'target_conditions': [
-                #     ['_toolset=="host"', {
-                #       'libraries': [
-                #         '-lrt'
-                #       ]
-                #     }]
-                #   ]
-                # },
-                #
-                # but we can't do this right now, as the AOSP does not support
-                # linking against the host librt, so we need to work around this
-                # for now, using the following hack (see platform/time.cc):
-                'target_conditions': [
-                  ['_toolset=="host"', {
-                    'defines': [
-                      'V8_LIBRT_NOT_AVAILABLE=1',
-                    ],
-                  }],
-                ],
                 'sources': [
                   '../../src/base/platform/platform-linux.cc'
                 ]
               }],
             ],
           },
         ],
         ['OS=="qnx"', {
             'link_settings': {
               'target_conditions': [
@@ skipping 382 matching lines @@
         }],
         ['want_separate_host_toolset==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }