Fix --disable-fast-text-autosizing.

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index 8792cdaed7b43c718fb09feaa769730ad98a7f0f..e83576464c59f42d80b82b70bf9c417c83aa2f53 100644
--- a/content/child/runtime_features.cc
+++ b/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);