Findbar slowness and losing of characters (cmd + F, typing)

[bsclifton]

• Did you search for similar issues before submitting this one?
  Yes. This is similar to Findbar slowness (cmd + F, typing) #10271

• Describe the issue you encountered:
  With a large number of windows / tabs open, the findbar will lose characters when first shown and typed into

• Platform (Win7, 8, 10? macOS? Linux distro?):
  macOS

• Brave Version (revision SHA):
  0.18.23

• Steps to reproduce:

  1. Have 13 or more windows open (each having multiple tabs- ~20 tabs total)
  2. Ensure Brave has the "start with my windows / tabs from last time" setting picked in preferences
  3. Quit Brave
  4. Relaunch Brave and while one of the pages is loading, use Cmd + F
  5. Try (quickly) searching for a term you know is on the page

• Actual result:
  Some characters are lost- For example, if you type "github" you may only see the "b" in the findbar

• Expected result:
  No characters are lost

• Will the steps above reproduce in a fresh profile? If not what other info can be added?

• Is this an issue in the currently released version?

• Can this issue be consistently reproduced?
  yes - although more granular / specific steps would be appreciated

• Extra QA steps:
  1.
  2.
  3.

• Screenshot if needed:

• Any related issues:

[ghost]

@bsclifton - My result when trying to reproduce is that as each window launches the focus in the the URL bar so even though I hit cmd+f and start typing, the words appear in the URL bar. When the search dialogue completes loading, typing moves there but characters are not lost. This was with about 20 windows, each with several tabs, opening. Severely strained my new mbp!