[QRCode Desktop] Crash fix: don't hide icon on close or teardown.

Fixes crash when using a keyboard shortcut to close the active tab with
the bubble open.

Note with recent changes, the icon intentionally stays visible after
bubble close, so this call is no longer needed anyway.

Bug: 1107857
Change-Id: Ic254f28522e3b405591d068d2395aa4f4f281f40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2314696Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Travis Skare <skare@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791016}

chrome/browser/ui/qrcode_generator/qrcode_generator_bubble_controller.cc

@@ -65,8 +65,6 @@ QRCodeGeneratorBubbleController::qrcode_generator_bubble_view() const {
 
 void QRCodeGeneratorBubbleController::OnBubbleClosed() {
   qrcode_generator_bubble_ = nullptr;
-  Browser* browser = chrome::FindBrowserWithWebContents(web_contents_);
-  browser->window()->UpdatePageActionIcon(PageActionIconType::kQRCodeGenerator);
 }
 
 QRCodeGeneratorBubbleController::QRCodeGeneratorBubbleController() = default;