Move LayoutTest Linux distribution detection to PlatformInfo

Tools/Scripts/webkitpy/common/system/platforminfo_mock.py

 # Copyright (C) 2011 Google Inc. 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
@@ skipping 10 matching lines @@
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 class MockPlatformInfo(object):
-    def __init__(self, os_name='mac', os_version='snowleopard', is_highdpi=False):
+    def __init__(self, os_name='mac', os_version='snowleopard', linux_distribution=None, is_highdpi=False):
         self.os_name = os_name
         self.os_version = os_version
+        self._linux_distribution = linux_distribution
         self._is_highdpi = is_highdpi
 
     def is_mac(self):
         return self.os_name == 'mac'
 
     def is_linux(self):
         return self.os_name == 'linux'
 
     def is_win(self):
         return self.os_name == 'win'
 
     def is_highdpi(self):
         return self._is_highdpi
 
     def is_cygwin(self):
         return self.os_name == 'cygwin'
 
     def is_freebsd(self):
         return self.os_name == 'freebsd'
 
     def display_name(self):
         return "MockPlatform 1.0"
 
+    def linux_distribution(self):
+        return self._linux_distribution if self.is_linux() else None
+
     def total_bytes_memory(self):
         return 3 * 1024 * 1024 * 1024  # 3GB is a reasonable amount of ram to mock.
 
     def terminal_width(self):
         return 80