Load LLVMpipe GL driver in Chromoting desktop session

remoting/host/linux/linux_me2me_host.py

Index: remoting/host/linux/linux_me2me_host.py
diff --git a/remoting/host/linux/linux_me2me_host.py b/remoting/host/linux/linux_me2me_host.py
index 8adca6e6502e853d492a8386f1dac049c785381b..864db543f04022ecbe33bde29f715dc38c664d05 100755
--- a/remoting/host/linux/linux_me2me_host.py
+++ b/remoting/host/linux/linux_me2me_host.py
@@ -20,6 +20,7 @@ import logging
 import optparse
 import os
 import pipes
+import platform
 import psutil
 import platform
 import signal
@@ -254,6 +255,14 @@ class Desktop:
       if os.environ.has_key(key):
         self.child_env[key] = os.environ[key]
 
+    # Ensure that the software-rendering GL drivers are loaded by the desktop
+    # session, instead of any hardware GL drivers installed on the system.
+    self.child_env["LD_LIBRARY_PATH"] = (
+        "/usr/lib/%(arch)s-linux-gnu/mesa:"
+        "/usr/lib/%(arch)s-linux-gnu/dri:"
+        "/usr/lib/%(arch)s-linux-gnu/gallium-pipe" %
+        { "arch": platform.machine() })
+
     # Read from /etc/environment if it exists, as it is a standard place to
     # store system-wide environment settings. During a normal login, this would
     # typically be done by the pam_env PAM module, depending on the local PAM