Tweak HSL lightness shift from 0.75 to 0.6

This HSL shift effect is used to present disabled or grayed-out versions
of app icons and tab favicons.

Changing this (from 0.75) in two places:

chrome/browser/ui/app_list/arc/arc_app_icon_loader.cc:61
chrome/browser/ui/extensions/icon_with_badge_image_source.cc:85

makes it consistent with four other places (which already used 0.6):

chrome/browser/extensions/chrome_app_icon.cc:83
chrome/browser/extensions/extension_icon_manager.cc:77
chrome/browser/favicon/favicon_utils.cc:26
chrome/browser/ui/app_list/chrome_app_list_item.cc:48

Change-Id: I67fbf5e0522ec17f8a248868091a8a624241e62f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1496131Reviewed-by: Yury Khmel <khmel@chromium.org>
Reviewed-by: Ben Wells <benwells@chromium.org>
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637903}

chrome/browser/ui/app_list/arc/arc_app_icon_loader.cc

@@ -58,7 +58,7 @@ void ArcAppIconLoader::UpdateImage(const std::string& app_id) {
       arc_prefs_->GetApp(app_id);
   if (app_info && app_info->suspended) {
     image =
-        gfx::ImageSkiaOperations::CreateHSLShiftedImage(image, {-1, 0, 0.75});
+        gfx::ImageSkiaOperations::CreateHSLShiftedImage(image, {-1, 0, 0.6});
   }
 
   delegate()->OnAppImageUpdated(app_id, image);

chrome/browser/ui/extensions/icon_with_badge_image_source.cc

@@ -82,7 +82,7 @@ void IconWithBadgeImageSource::Draw(gfx::Canvas* canvas) {
         rep, ExtensionAction::ActionIconSize(), canvas->image_scale()));
   }
   if (grayscale_)
-    skia = gfx::ImageSkiaOperations::CreateHSLShiftedImage(skia, {-1, 0, 0.75});
+    skia = gfx::ImageSkiaOperations::CreateHSLShiftedImage(skia, {-1, 0, 0.6});
 
   int x_offset =
       std::floor((size().width() - ExtensionAction::ActionIconSize()) / 2.0);