[Sheriffing] Removing dependency from GN file

Previous change forgot to remove a file from BUILD.gn

https://codereview.chromium.org/479873002

BUG=None
NOTRY=true
TBR=jam

Review URL: https://codereview.chromium.org/587193004

Cr-Commit-Position: refs/heads/master@{#295966}

content/browser/BUILD.gn

@@ -249,8 +249,6 @@ source_set("browser") {
 
   if (use_x11) {
     configs += [ "//build/config/linux:x11" ]
-  } else {
-    sources -= [ "renderer_host/web_input_event_aurax11.cc" ]
   }
 
   # Dealing with power_save_blocker_{x11,ozone}.cc is a little complicated