Remove TileItemBackground from experimental app list.

This CL removes the white TileItemBackground from the tiles on the
experimental app list start page.

BUG=349727

Review URL: https://codereview.chromium.org/492153002

Cr-Commit-Position: refs/heads/master@{#291632}

ui/app_list/views/tile_item_view.cc

@@ -14,7 +14,6 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_analysis.h"
 #include "ui/gfx/color_utils.h"
-#include "ui/views/background.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
@@ -24,61 +23,15 @@ namespace {
 const int kTileSize = 90;
 const int kTileHorizontalPadding = 10;
 
-const SkColor kTileBackgroundColor = SK_ColorWHITE;
-const int kTileColorStripHeight = 2;
-const SkAlpha kTileColorStripOpacity = 0X5F;
-const int kTileCornerRadius = 2;
-
 }  // namespace
 
 namespace app_list {
 
-// A background for the start page item view which consists of a rounded rect
-// with a dominant color strip at the bottom.
-class TileItemView::TileItemBackground : public views::Background {
- public:
-  TileItemBackground() : strip_color_(SK_ColorBLACK) {}
-  virtual ~TileItemBackground() {}
-
-  void set_strip_color(SkColor strip_color) { strip_color_ = strip_color; }
-
-  // Overridden from views::Background:
-  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
-    SkPaint paint;
-    paint.setFlags(SkPaint::kAntiAlias_Flag);
-
-    // Paint the border.
-    paint.setColor(kStartPageBorderColor);
-    canvas->DrawRoundRect(view->GetContentsBounds(), kTileCornerRadius, paint);
-
-    // Paint a rectangle for the color strip.
-    gfx::Rect color_strip_rect(view->GetContentsBounds());
-    color_strip_rect.Inset(1, 1, 1, 1);
-    paint.setColor(SkColorSetA(strip_color_, kTileColorStripOpacity));
-    canvas->DrawRoundRect(color_strip_rect, kTileCornerRadius, paint);
-
-    // Paint the main background rectangle, leaving part of the color strip
-    // unobscured.
-    gfx::Rect static_background_rect(color_strip_rect);
-    static_background_rect.Inset(0, 0, 0, kTileColorStripHeight);
-    paint.setColor(kTileBackgroundColor);
-    canvas->DrawRoundRect(static_background_rect, kTileCornerRadius, paint);
-  }
-
- private:
-  SkColor strip_color_;
-
-  DISALLOW_COPY_AND_ASSIGN(TileItemBackground);
-};
-
 TileItemView::TileItemView()
     : views::CustomButton(this),
       item_(NULL),
       icon_(new views::ImageView),
-      title_(new views::Label),
-      background_(new TileItemBackground()) {
-  set_background(background_);
-
+      title_(new views::Label) {
   views::BoxLayout* layout_manager = new views::BoxLayout(
       views::BoxLayout::kVertical, kTileHorizontalPadding, 0, 0);
   layout_manager->set_main_axis_alignment(
@@ -141,9 +94,6 @@ void TileItemView::ButtonPressed(views::Button* sender,
 
 void TileItemView::OnIconChanged() {
   icon_->SetImage(item_->icon());
-  background_->set_strip_color(
-      color_utils::CalculateKMeanColorOfBitmap(*item_->icon().bitmap()));
-  SchedulePaint();
 }
 
 void TileItemView::OnResultDestroying() {

ui/app_list/views/tile_item_view.h

@@ -30,8 +30,6 @@ class APP_LIST_EXPORT TileItemView : public views::CustomButton,
   void SetSearchResult(SearchResult* item);
 
  private:
-  class TileItemBackground;
-
   // Overridden from views::View:
   virtual gfx::Size GetPreferredSize() const OVERRIDE;
 
@@ -49,8 +47,6 @@ class APP_LIST_EXPORT TileItemView : public views::CustomButton,
   views::ImageView* icon_;  // Owned by views hierarchy.
   views::Label* title_;     // Owned by views hierarchy.
 
-  TileItemBackground* background_;
-
   DISALLOW_COPY_AND_ASSIGN(TileItemView);
 };