Remove a few more remnants of the internal remoting plugin.

BUG=510271

Review URL: https://codereview.chromium.org/1266923005

Cr-Original-Commit-Position: refs/heads/master@{#341908}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 7776f2bce4099de007033efa1fa5f01a4d9d137b

common.gypi

@@ -2101,9 +2101,6 @@
       ['image_loader_extension==1', {
         'grit_defines': ['-D', 'image_loader_extension'],
       }],
-      ['remoting==1', {
-        'grit_defines': ['-D', 'remoting'],
-      }],
       ['use_titlecase_in_grd==1', {
         'grit_defines': ['-D', 'use_titlecase'],
       }],
@@ -2760,9 +2757,6 @@
       ['profiling==1', {
         'defines': ['ENABLE_PROFILING=1'],
       }],
-      ['remoting==1', {
-        'defines': ['ENABLE_REMOTING=1'],
-      }],
       ['enable_webrtc==1', {
         'defines': ['ENABLE_WEBRTC=1'],
       }],

config/BUILD.gn

@@ -222,9 +222,6 @@ config("feature_flags") {
   if (enable_image_loader_extension) {
     defines += [ "IMAGE_LOADER_EXTENSION=1" ]
   }
-  if (enable_remoting) {
-    defines += [ "ENABLE_REMOTING=1" ]
-  }
   if (enable_google_now) {
     defines += [ "ENABLE_GOOGLE_NOW=1" ]
   }

secondary/tools/grit/grit_rule.gni

@@ -168,13 +168,6 @@ if (enable_image_loader_extension) {
   ]
 }
 
-if (enable_remoting) {
-  grit_defines += [
-    "-D",
-    "remoting",
-  ]
-}
-
 if (is_android) {
   grit_defines += [
     "-t",