Make tab tooltip behavior consistent across all desktop platforms.

chrome/browser/ui/views/tabs/tab.cc

 // 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.
 
 #include "chrome/browser/ui/views/tabs/tab.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/debug/alias.h"
@@ skipping 909 matching lines @@
     if (clip.size().GetArea()) {
       SkRect intersection(path->getBounds());
       intersection.intersect(RectToSkRect(clip));
       path->reset();
       path->addRect(intersection);
     }
   }
 }
 
 bool Tab::GetTooltipText(const gfx::Point& p, base::string16* tooltip) const {
-  // TODO(miu): Rectify inconsistent tooltip behavior.  http://crbug.com/310947
-
-  if (data_.media_state != TAB_MEDIA_STATE_NONE) {
-    *tooltip = chrome::AssembleTabTooltipText(data_.title, data_.media_state);
-    return true;
-  }
-
-  if (data_.title.empty())
-    return false;
-
-  // Only show the tooltip if the title is truncated.
-  if (font_->GetStringWidth(data_.title) > GetTitleBounds().width()) {
-    *tooltip = data_.title;
-    return true;
-  }
-  return false;
+  // Note: Anything that affects the tooltip text should be accounted for when
+  // calling TooltipTextChanged() from Tab::DataChanged().
+  *tooltip = chrome::AssembleTabTooltipText(data_.title, data_.media_state);
+  return !tooltip->empty();
 }
 
 bool Tab::GetTooltipTextOrigin(const gfx::Point& p, gfx::Point* origin) const {
   origin->set_x(title_bounds_.x() + 10);
   origin->set_y(-views::TooltipManager::GetTooltipHeight() - 4);
   return true;
 }
 
 ui::ThemeProvider* Tab::GetThemeProvider() const {
   ui::ThemeProvider* tp = View::GetThemeProvider();
@@ skipping 165 matching lines @@
     return;
   const int mini_delta = kMiniTabRendererAsNormalTabWidth - GetMiniWidth();
   const int ideal_delta = width() - GetMiniWidth();
   const int ideal_x = (GetMiniWidth() - bounds->width()) / 2;
   bounds->set_x(bounds->x() + static_cast<int>(
       (1 - static_cast<float>(ideal_delta) / static_cast<float>(mini_delta)) *
       (ideal_x - bounds->x())));
 }
 
 void Tab::DataChanged(const TabRendererData& old) {
+  if (data().media_state != old.media_state || data().title != old.title)
+    TooltipTextChanged();
+
   if (data().blocked == old.blocked)
     return;
 
   if (data().blocked)
     StartPulse();
   else
     StopPulse();
 }
 
 void Tab::PaintTab(gfx::Canvas* canvas) {
@@ skipping 632 matching lines @@
                          const gfx::ImageSkia& image) {
   DCHECK_NE(scale_factor, ui::SCALE_FACTOR_NONE);
   ImageCacheEntry entry;
   entry.resource_id = resource_id;
   entry.scale_factor = scale_factor;
   entry.image = image;
   image_cache_->push_front(entry);
   if (image_cache_->size() > kMaxImageCacheSize)
     image_cache_->pop_back();
 }