Fix --disable-fast-text-autosizing.

This has been broken since https://src.chromium.org/viewvc/blink?revision=172846&view=revision landed.

Review URL: https://codereview.chromium.org/276983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269623 0039d316-1c4b-4281-b951-d872f2087c98

content/child/runtime_features.cc

@@ -135,10 +135,12 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   if (ui::IsOverlayScrollbarEnabled())
     WebRuntimeFeatures::enableOverlayScrollbars(true);
 
-  if (command_line.HasSwitch(switches::kEnableFastTextAutosizing)
-      && !command_line.HasSwitch(switches::kDisableFastTextAutosizing))
+  if (command_line.HasSwitch(switches::kEnableFastTextAutosizing))
     WebRuntimeFeatures::enableFastTextAutosizing(true);
 
+  if (command_line.HasSwitch(switches::kDisableFastTextAutosizing))
+    WebRuntimeFeatures::enableFastTextAutosizing(false);
+
   if (command_line.HasSwitch(switches::kDisableRepaintAfterLayout))
     WebRuntimeFeatures::enableRepaintAfterLayout(false);