Mac:Dont always enable findbar buttons when restoring focus with search string

chrome/browser/ui/cocoa/find_bar/find_bar_cocoa_controller.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/auto_reset.h"
 #include "base/mac/bundle_locations.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/app/vector_icons/vector_icons.h"
@@ skipping 344 matching lines @@
     showHideAnimation_.reset(nil);
   }
   if (moveAnimation_.get()) {
     [moveAnimation_ stopAnimation];
     moveAnimation_.reset(nil);
   }
 }
 
 - (void)setFocusAndSelection {
   [[findText_ window] makeFirstResponder:findText_];
-
-  // Enable the buttons if the find text is non-empty.

[rohitrao (ping after 24h), 2017/06/26 13:20:15]

Here's a case that appears to have regressed with this CL.  Can you also
reproduce this locally?

1) Open two tabs.
2) Search for something (with matches) in the first tab.
3) Close the find bar.  Switch to the second tab.  Switch back.
4) Press Cmd-F to open the find bar again.

At this point, I see the find bar, populated with a search string, but the
buttons are disabled.  I think I'd expect the buttons to be enabled at this
point?  Otherwise there's no way to trigger a search except by using the
keyboard shortcuts or deleting and retyping the text.

-  BOOL buttonsEnabled = ([[findText_ stringValue] length] > 0) ? YES : NO;

[rohitrao (ping after 24h), 2017/06/26 13:20:15]

So it seems that this function is called from at least one place where it's
important to set the button state correctly, and doing nothing doesn't work.

Maybe we need to continue setting the state, but use different logic for
|buttonsEnabled|?  We could look at whether or not there is an active find
operation, and if so, use the current results to set the enabled states.

[carloschilazo, 2017/06/28 22:50:22]

Thanks for looking into it Rohit! I agree, we need to then add logic for the
enablement instead of directly removing it. I'll make some time this weekend to
look into it.

-  [previousButton_ setEnabled:buttonsEnabled];
-  [nextButton_ setEnabled:buttonsEnabled];
 }
 
 - (void)restoreSavedFocus {
   if (!(focusTracker_.get() &&
         [focusTracker_ restoreFocusInWindow:[findBarView_ window]])) {
     // Fall back to giving focus to the tab contents.
     findBarBridge_->GetFindBarController()->web_contents()->Focus();
   }
   focusTracker_.reset(nil);
 }
@@ skipping 282 matching lines @@
 }
 
 - (BrowserWindowController*)browserWindowController {
   if (!browser_)
     return nil;
   return [BrowserWindowController
       browserWindowControllerForWindow:browser_->window()->GetNativeWindow()];
 }
 
 @end