Add heuristics to limit showing of new backspace UI bubble.

chrome/browser/ui/views/frame/browser_view.cc

 // Copyright 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.
 
 #include "chrome/browser/ui/views/frame/browser_view.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 940 matching lines @@
     ExclusiveAccessBubbleType bubble_type) {
   // Immersive mode has no exit bubble because it has a visible strip at the
   // top that gives the user a hover target.
   // TODO(jamescook): Figure out what to do with mouse-lock.
   if (bubble_type == EXCLUSIVE_ACCESS_BUBBLE_TYPE_NONE ||
       ShouldUseImmersiveFullscreenForUrl(url)) {
     exclusive_access_bubble_.reset();
     return;
   }
 
+  if (exclusive_access_bubble_) {
+    exclusive_access_bubble_->UpdateContent(url, bubble_type);
+    return;
+  }
+
   // Hide the backspace shortcut bubble, to avoid overlapping.
   new_back_shortcut_bubble_.reset();
 
-  if (exclusive_access_bubble_) {
-    exclusive_access_bubble_->UpdateContent(url, bubble_type);
-  } else {
-    exclusive_access_bubble_.reset(
-        new ExclusiveAccessBubbleViews(this, url, bubble_type));
-  }
+  exclusive_access_bubble_.reset(
+      new ExclusiveAccessBubbleViews(this, url, bubble_type));
 }
 
 void BrowserView::OnExclusiveAccessUserInput() {
   if (exclusive_access_bubble_.get())
     exclusive_access_bubble_->OnUserInput();
 }
 
 bool BrowserView::ShouldHideUIForFullscreen() const {
   // Immersive mode needs UI for the slide-down top panel.
   if (immersive_mode_controller_->IsEnabled())
     return false;
 
   return IsFullscreen();
 }
 
 bool BrowserView::IsFullscreen() const {
   return frame_->IsFullscreen();
 }
 
 bool BrowserView::IsFullscreenBubbleVisible() const {
   return exclusive_access_bubble_ != nullptr;
 }
 
-void BrowserView::ShowNewBackShortcutBubble(bool forward) {
-  // Hide the exclusive access bubble, to avoid overlapping.
-  exclusive_access_bubble_.reset();
+void BrowserView::MaybeShowNewBackShortcutBubble(bool forward) {
+  if (!new_back_shortcut_bubble_ || !new_back_shortcut_bubble_->IsVisible()) {
+    // Show the bubble at most five times.
+    PrefService* prefs = browser_->profile()->GetPrefs();
+    int shown_count = prefs->GetInteger(prefs::kBackShortcutBubbleShownCount);
+    constexpr int kMaxShownCount = 5;
+    if (shown_count >= kMaxShownCount)
+      return;
 
+    // Only show the bubble when the user presses a shortcut twice within three
+    // seconds.
+    const base::TimeTicks now = base::TimeTicks::Now();
+    constexpr base::TimeDelta kRepeatWindow = base::TimeDelta::FromSeconds(3);
+    if (last_back_shortcut_press_time_.is_null() ||
+        ((now - last_back_shortcut_press_time_) > kRepeatWindow)) {
+      last_back_shortcut_press_time_ = now;
+      return;
+    }
+
+    // Hide the exclusive access bubble, to avoid overlapping.
+    exclusive_access_bubble_.reset();
+
+    new_back_shortcut_bubble_.reset(new NewBackShortcutBubble(this));
+    prefs->SetInteger(prefs::kBackShortcutBubbleShownCount, shown_count + 1);
+    last_back_shortcut_press_time_ = base::TimeTicks();
+  }
+
+  new_back_shortcut_bubble_->UpdateContent(forward);
+}
+
+void BrowserView::HideNewBackShortcutBubble() {
   if (new_back_shortcut_bubble_)
-    new_back_shortcut_bubble_->UpdateContent(forward);
-  else
-    new_back_shortcut_bubble_.reset(new NewBackShortcutBubble(this, forward));
+    new_back_shortcut_bubble_->Hide();
 }
 
 void BrowserView::RestoreFocus() {
   WebContents* selected_web_contents = GetActiveWebContents();
   if (selected_web_contents)
     selected_web_contents->RestoreFocus();
 }
 
 void BrowserView::FullscreenStateChanged() {
   CHECK(!IsFullscreen());
@@ skipping 1616 matching lines @@
 }
 
 extensions::ActiveTabPermissionGranter*
 BrowserView::GetActiveTabPermissionGranter() {
   content::WebContents* web_contents = GetActiveWebContents();
   if (!web_contents)
     return nullptr;
   return extensions::TabHelper::FromWebContents(web_contents)
       ->active_tab_permission_granter();
 }