Enable find in page buttons based on search text rather than match

results.

When you re-open the find bar and it's prepopulated with a previous
search, we don't execute a search until you press enter or
next/previous. Before this patch, next/previous was disabled when you
have prepopulated search text but no actual search.

BUG=627356

Review-Url: https://codereview.chromium.org/2143703002
Cr-Commit-Position: refs/heads/master@{#405205}

chrome/browser/ui/views/find_bar_view.cc

@@ -594,7 +594,7 @@ void FindBarView::Find(const base::string16& search_text) {
 }
 
 void FindBarView::UpdateMatchCountAppearance(bool no_match) {
-  bool enable_buttons = !match_count_text_->text().empty() && !no_match;
+  bool enable_buttons = !find_text_->text().empty() && !no_match;
   find_previous_button_->SetEnabled(enable_buttons);
   find_next_button_->SetEnabled(enable_buttons);