Number of matches still shows after clearing findbar

[cndouglas]

Did you search for similar issues before submitting this one?
Yes. Did not find anything.

Describe the issue you encountered:
After clicking the findbar clear button, the number of matches is still shown.

Expected behavior:
The number of matches should disappear.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  macOS 10.12.1
• Brave Version:
  0.12.7
• Steps to reproduce:
  1. Open Brave and navigate to any page.
  2. Open the findbar and type in a word that is on the page.
  3. Notice the number of matches (e.g., 1 of 2).
  4. Click the clear button.
  5. Notice that the number of matches is still shown.
• Screenshot if needed:
  
• Any related issues:
  This is a continuation of a few recent issues related to the findbar (Findbar clear button isn't working #4965 and After clicking findbar clear button, old search terms are still highlighted #5110). However, I think I found a fix that should resolve these recurring problems for good. 😉 I will submit a PR shortly.