Add heuristics to limit showing of new backspace UI bubble.

chrome/browser/ui/views/new_back_shortcut_bubble.cc

 // Copyright 2016 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/new_back_shortcut_bubble.h"
 
 #include <utility>
 
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 15 matching lines @@
 namespace {
 
 const int kPopupTopPx = 45;
 const int kSlideInDurationMs = 350;
 const int kSlideOutDurationMs = 700;
 const int kShowDurationMs = 3800;
 
 }
 
 NewBackShortcutBubble::NewBackShortcutBubble(
-    ExclusiveAccessBubbleViewsContext* context,
-    bool forward)
+    ExclusiveAccessBubbleViewsContext* context)
     : bubble_view_context_(context),
       animation_(new gfx::SlideAnimation(this)),
       view_(new SubtleNotificationView(nullptr)),
       popup_(SubtleNotificationView::CreatePopupWidget(
           bubble_view_context_->GetBubbleParentView(),
           view_,
           false)) {
-  UpdateContent(forward);

[Peter Kasting, 2016/06/07 08:04:23]

Removing this was not strictly necessary, but did let me slightly simplify the
caller logic (to just unconditionally call UpdateContent()).  Of course, I could
have done that without removing this, but then this call would be completely
redundant.

[Matt Giuca, 2016/06/08 01:29:03]

OK. I commented about this in the top of
BrowserView::MaybeShowNewBackShortcutBubble.

 }
 
 NewBackShortcutBubble::~NewBackShortcutBubble() {
   // We might need to delete the widget asynchronously. See rationale in
   // ~ExclusiveAccessBubbleViews.
   popup_->Close();
   base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, popup_);
 }
 
+bool NewBackShortcutBubble::IsVisible() const {
+  return popup_->IsVisible();
+}
+
 void NewBackShortcutBubble::UpdateContent(bool forward) {
   // Note: The key names are parameters so that we can vary by operating system
   // or change the direction of the arrow as necessary (see
   // https://crbug.com/612685).
 
 #if defined(OS_MACOSX)
   // U+2318 = PLACE OF INTEREST SIGN (Mac Command symbol).
   base::string16 accelerator = base::WideToUTF16(L"\x2318");
 #else
   base::string16 accelerator = l10n_util::GetStringUTF16(IDS_APP_ALT_KEY);
@@ skipping 13 matching lines @@
   // Show the bubble.
   animation_->SetSlideDuration(kSlideInDurationMs);
   animation_->Show();
 
   // Wait a few seconds before hiding.
   hide_timeout_.Start(FROM_HERE,
                       base::TimeDelta::FromMilliseconds(kShowDurationMs), this,
                       &NewBackShortcutBubble::OnTimerElapsed);
 }
 
+void NewBackShortcutBubble::Hide() {
+  hide_timeout_.Stop();
+  OnTimerElapsed();
+}
+
 void NewBackShortcutBubble::AnimationProgressed(
     const gfx::Animation* animation) {
   float opacity = static_cast<float>(animation_->CurrentValueBetween(0.0, 1.0));
   if (opacity == 0) {
     popup_->Hide();
   } else {
     if (!popup_->IsVisible())
       popup_->Show();
 
     popup_->SetOpacity(opacity);
@@ skipping 13 matching lines @@
   int desired_top = kPopupTopPx - view_->border()->GetInsets().top();
   int y = widget_bounds.y() + desired_top;
   return gfx::Rect(gfx::Point(x, y), size);
 }
 
 void NewBackShortcutBubble::OnTimerElapsed() {
   // Hide the bubble.
   animation_->SetSlideDuration(kSlideOutDurationMs);
   animation_->Hide();
 }