Revert of Sandbox html_viewer on Linux.

mojo/runner/child_process.cc

Index: mojo/runner/child_process.cc
diff --git a/mojo/runner/child_process.cc b/mojo/runner/child_process.cc
index 39c740a1981f04d5cef86b969f3cf5bf88fd543b..996693429741919218ca8bca0c617128ff14e4f7 100644
--- a/mojo/runner/child_process.cc
+++ b/mojo/runner/child_process.cc
@@ -310,13 +310,7 @@
       if (sandbox_warm)
         sandbox_warm();
 
-      // TODO(erg,jln): Allowing access to all of /dev/shm/ makes it easy to
-      // spy on other shared memory using processes. This is a temporary hack
-      // so that we have some sandbox until we have proper shared memory
-      // support integrated into mojo.
       std::vector<BrokerFilePermission> permissions;
-      permissions.push_back(
-          BrokerFilePermission::ReadWriteCreateUnlinkRecursive("/dev/shm/"));
       sandbox.reset(new mandoline::LinuxSandbox(permissions));
       sandbox->Warmup();
       sandbox->EngageNamespaceSandbox();