fix text color of BlueButton on GTK-theme-mode Linux Aura.

chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc

 // Copyright (c) 2013 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/libgtk2ui/native_theme_gtk2.h"
 
 #include <gtk/gtk.h>
 
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
 #include "chrome/browser/ui/libgtk2ui/skia_utils_gtk2.h"
@@ skipping 218 matching lines @@
     case kColorId_ButtonEnabledColor:
       return GetButtonStyle()->text[GTK_STATE_NORMAL];
     case kColorId_ButtonDisabledColor:
       return GetButtonStyle()->text[GTK_STATE_INSENSITIVE];
     case kColorId_ButtonHighlightColor:
       return GetButtonStyle()->base[GTK_STATE_SELECTED];
     case kColorId_ButtonHoverColor:
       return GetButtonStyle()->text[GTK_STATE_PRELIGHT];
     case kColorId_ButtonHoverBackgroundColor:
       return GetButtonStyle()->bg[GTK_STATE_PRELIGHT];
+    // TODO(estade): determine a more distinct color for the CallToAction

[msw, 2014/06/02 21:06:20]

How about using the existing button colors above (with the same values here),
and doing SetAutoColorReadabilityEnabled on the label to handle cases where the
system colors don't work? Perhaps that will typically yield white as
expected/spec'ed, and it seems like we ought to use readable versions of the
system colors anyway.

[Evan Stade, 2014/06/02 22:18:14]

I don't follow. This code just makes blue buttons look like normal buttons.
There's no other option right now, except to make blue buttons never be themed,
which looks way worse IMO.

[msw, 2014/06/02 22:39:44]

Yeah, I suggest (1) using readable versions of these normal button text colors.
We need readable colors because users with blue text colors won't be able to
read blue text on blue buttons.

I'm also suggesting (2) possibly removing these new color ids. I'm hoping that
we can just use the normal color ids (like kColorId_ButtonEnabledColor above)
everywhere and still get something legible and close to spec.

+    // buttons.
+    case kColorId_CallToActionButtonEnabledColor:

[msw, 2014/06/03 22:20:41]

Rename these kColorId_BlueButton*, or rename BlueButton CallToActionButton. I
like the more intent-related name, but consistency is more important until you
want to do a wider rename.

[Evan Stade, 2014/06/03 23:16:12]

Done.

This reminds me of the part of Earthworm Jim where a quiz show asks you "What
color is Jim's red gun?"

[msw, 2014/06/03 23:24:52]

FYI, you haven't uploaded the latest patch set with this change.

[Evan Stade, 2014/06/04 00:12:10]

Done.

+      return GetButtonStyle()->text[GTK_STATE_NORMAL];
+    case kColorId_CallToActionButtonDisabledColor:
+      return GetButtonStyle()->text[GTK_STATE_INSENSITIVE];
+    case kColorId_CallToActionButtonHighlightColor:
+      return GetButtonStyle()->base[GTK_STATE_SELECTED];
+    case kColorId_CallToActionButtonHoverColor:
+      return GetButtonStyle()->text[GTK_STATE_PRELIGHT];
 
     // Textfield
     case kColorId_TextfieldDefaultColor:
       return GetEntryStyle()->text[GTK_STATE_NORMAL];
     case kColorId_TextfieldDefaultBackground:
       return GetEntryStyle()->base[GTK_STATE_NORMAL];
     case kColorId_TextfieldReadOnlyColor:
       return GetEntryStyle()->text[GTK_STATE_INSENSITIVE];
     case kColorId_TextfieldReadOnlyBackground:
       return GetEntryStyle()->base[GTK_STATE_INSENSITIVE];
@@ skipping 155 matching lines @@
       fake_menu_.Own(gtk_custom_menu_new());
 
     fake_menu_item_ = gtk_custom_menu_item_new();
     gtk_menu_shell_append(GTK_MENU_SHELL(fake_menu_.get()), fake_menu_item_);
   }
 
   return gtk_rc_get_style(fake_menu_item_);
 }
 
 }  // namespace libgtk2ui