Disable RegisterProtocolHandler on Linux.

build/common.gypi

 # Copyright (c) 2011 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 111 matching lines @@
       # it can be overriden by the GYP command line or by ~/.gyp/include.gypi.
       'component%': 'static_library',
 
       # Set to select the Title Case versions of strings in GRD files.
       'use_titlecase_in_grd_files%': 0,
 
       # Use translations provided by volunteers at launchpad.net.  This
       # currently only works on Linux.
       'use_third_party_translations%': 0,
 
-      # Enable navigator.registerProtocolHandler and supporting UI.
-      'enable_register_protocol_handler%': 1,
-
       # Remoting compilation is enabled by default. Set to 0 to disable.
       'remoting%': 1,
 
       # P2P APIs are compiled in by default. Set to 0 to disable.
       # Also note that this should be enabled for remoting to compile.
       'p2p_apis%': 1,
 
       # Configuration policy is enabled by default. Set to 0 to disable.
       'configuration_policy%': 1,
 
@@ skipping 49 matching lines @@
         }, {
           'enable_flapper_hacks%': 0,
         }],
 
         # Enable file manager extension by default on Chrome OS.
         ['chromeos==1', {
           'file_manager_extension%': 1,
         }, {
           'file_manager_extension%': 0,
         }],
+
+        # Enable navigator.registerProtocolHandler and supporting UI.
+        # We disable on Linux because the OS-level component of RPH isn't
+        # implemented.
+        ['OS=="linux"', {
+          'enable_register_protocol_handler%': 0,
+        }, {
+          'enable_register_protocol_handler%': 1,
+        }],
       ],
     },
 
     # Copy conditionally-set variables out one scope.
     'branding%': '<(branding)',
     'buildtype%': '<(buildtype)',
     'target_arch%': '<(target_arch)',
     'host_arch%': '<(host_arch)',
     'library%': 'static_library',
     'toolkit_views%': '<(toolkit_views)',
@@ skipping 1537 matching lines @@
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: