Allow background tab titles to use LCD AA.

chrome/browser/ui/views/tabs/tab_strip.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_strip.h"
 
 #include <algorithm>
 #include <iterator>
 #include <string>
 #include <vector>
@@ skipping 1414 matching lines @@
 void TabStrip::PaintChildren(const ui::PaintContext& context) {
   // The view order doesn't match the paint order (tabs_ contains the tab
   // ordering). Additionally we need to paint the tabs that are closing in
   // |tabs_closing_map_|.
   bool is_dragging = false;
   Tab* active_tab = NULL;
   Tabs tabs_dragging;
   Tabs selected_tabs;
 
   {
-    // TODO(pkasting): This results in greyscale AA for the tab titles.  Work
-    // with Mike Reed to fix, or else convert to passing the tabs a memory
-    // canvas to paint on and then manually compositing.
+    // We pass false for |lcd_text_requires_opaque_layer| so that background

[danakj, 2015/12/11 22:44:02]

Ya this works :)

+    // tab titles will get LCD AA.  These are rendered opaquely on an opaque tab
+    // background before the layer is composited, so this is safe.
     ui::CompositingRecorder opacity_recorder(context, size(),
-                                             GetInactiveAlpha(false));
+                                             GetInactiveAlpha(false), false);
 
     PaintClosingTabs(tab_count(), context);
 
     int active_tab_index = -1;
     for (int i = tab_count() - 1; i >= 0; --i) {
       Tab* tab = tab_at(i);
       if (tab->dragging() && !stacked_layout_) {
         is_dragging = true;
         if (tab->IsActive()) {
           active_tab = tab;
@@ skipping 36 matching lines @@
 
   // Next comes the active tab.
   if (active_tab && !is_dragging)
     active_tab->Paint(context);
 
   // Paint the New Tab button.
   const bool md = ui::MaterialDesignController::IsModeMaterial();
   if (md && (newtab_button_->state() != views::CustomButton::STATE_PRESSED)) {
     // Match the inactive tab opacity for non-pressed states.  See comments in
     // NewTabButton::PaintFill() for why we don't do this for the pressed state.
+    // This call doesn't need to set |lcd_text_requires_opaque_layer| to false
+    // because no text will be drawn.
     ui::CompositingRecorder opacity_recorder(context, size(),
-                                             GetInactiveAlpha(true));
+                                             GetInactiveAlpha(true), true);
     newtab_button_->Paint(context);
   } else {
     newtab_button_->Paint(context);
   }
 
   // And the dragged tabs.
   for (size_t i = 0; i < tabs_dragging.size(); ++i)
     tabs_dragging[i]->Paint(context);
 
   // If the active tab is being dragged, it goes last.
@@ skipping 1342 matching lines @@
           ConvertPointToViewAndGetEventHandler(this, newtab_button_, point);
       if (view)
         return view;
     }
     Tab* tab = FindTabForEvent(point);
     if (tab)
       return ConvertPointToViewAndGetEventHandler(this, tab, point);
   }
   return this;
 }