Add ability to constrain dominant color selection to a HSL range.

ui/app_list/views/tile_item_view.cc

 // Copyright 2014 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 "ui/app_list/views/tile_item_view.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
@@ skipping 87 matching lines @@
     SetVisible(false);
     icon_->SetImage(NULL);
     title_->SetText(base::string16());
     return;
   }
 
   SetVisible(true);
   icon_->SetImage(item_->icon());
   title_->SetText(base::UTF8ToUTF16(item_->name()));
 
-  background_->set_strip_color(
-      color_utils::CalculateKMeanColorOfBitmap(*item_->icon().bitmap()));
+  color_utils::GridSampler sampler;
+  background_->set_strip_color(color_utils::CalculateKMeanColorOfPNG(

[Matt Giuca, 2014/05/22 05:03:52]

Ew, please don't convert to a PNG just to get around the fact that there is no
way to give explicit values to CalculateKMeanColorOfBitmap. See my comment on
that function.

Also: I think you should save this change for a follow-up CL. This CL should
just be changing the algorithm, not actually changing the parameters used by any
specific client. So in this CL, call the default overload of
CalculateKMeanColorOfBitmap.

[calamity, 2014/05/22 07:36:36]

Added overload in precursor CL.

+      gfx::Image(item_->icon()).As1xPNGBytes(),
+      color_utils::HSL{-1, 0.3, 0.2},
+      color_utils::HSL{-1, 1, 0.8},
+      &sampler));
 }
 
 gfx::Size TileItemView::GetPreferredSize() {
   return gfx::Size(kTileSize, kTileSize);
 }
 
 void TileItemView::ButtonPressed(views::Button* sender,
                                  const ui::Event& event) {
   item_->Activate(event.flags());
 }
 
 }  // namespace app_list