Partial revert: add hints to ChromeVox

ARC++ has no focus by when TalkBack is on design. Speaking this hint interferes with TalkBack.

Original change
https://chromium-review.googlesource.com/c/chromium/src/+/902405

Bug: 809083,806470, 806469
TBR=yawano@chromium.org,dmazzoni@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I84d3b635e6cca62c0bc152723d143cfabdcc0982
Reviewed-on: https://chromium-review.googlesource.com/925698
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Yuki Awano <yawano@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537749}

chrome/browser/resources/chromeos/chromevox/cvox2/background/command_handler.js

@@ -238,10 +238,8 @@ CommandHandler.onCommand = function(command) {
   }
 
   // Require a current range.
-  if (!ChromeVoxState.instance.currentRange_) {
-    new Output().format('@warning_no_current_range').go();
+  if (!ChromeVoxState.instance.currentRange_)
     return true;
-  }
 
   var current = ChromeVoxState.instance.currentRange_;