Use vector icon for Ash shelf launcher

ash/shelf/app_list_button.cc

Index: ash/shelf/app_list_button.cc
diff --git a/ash/shelf/app_list_button.cc b/ash/shelf/app_list_button.cc
index a57e12378802c6ebd7720ab4f09aae6c80058aa8..62a73eb99779e8b0ae12b6dd020ee1c21d2bfd3c 100644
--- a/ash/shelf/app_list_button.cc
+++ b/ash/shelf/app_list_button.cc
@@ -19,8 +19,20 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches_util.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/gfx/vector_icons_public.h"
 #include "ui/views/painter.h"
 
+namespace {
+// Width and height of the launcher icon, which includes 2px of internal
+// padding at each side.
+const int kLauncherIconSize = 18;

[tdanderson, 2016/05/23 21:18:24]

So if I remember our conversation correctly, the vectorization process bakes
some padding into the .icon, and there is no easy way to strip this out or add
to it. In this case, I wanted the search icon to appear as 14px (length from one
side of the magnifying glass to the other without any padding) so I had to play
around with sizes to determine that using 18 would give me a 14px magnifying
glass + 2px baked-in padding to the left + 2px of baked-in padding to the right.
Does this sound like what your workflow would be, or am I missing something?

[Evan Stade, 2016/05/23 22:11:57]

Overall, yes. One way to add to the padding would be to set an empty border on a
views::ImageView. In this case, the centering code you have looks reasonable.

+
+// Color of the launcher icon.
+// TODO(tdanderson): Move Ash color constants to a common location.
+const SkColor kLauncherIconColor = SK_ColorWHITE;
+}  // namespace
+
 namespace ash {
 
 AppListButton::AppListButton(ShelfView* shelf_view)
@@ -109,19 +121,17 @@ void AppListButton::OnPaint(gfx::Canvas* canvas) {
     else
       background_image_id = IDR_AURA_NOTIFICATION_BACKGROUND_NORMAL;
   }
+
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   const gfx::ImageSkia* background_image =
       rb.GetImageNamed(background_image_id).ToImageSkia();
-  // TODO(mgiuca): When the "classic" app list is removed, also remove this
-  // resource and its icon file.
-  int foreground_image_id = app_list::switches::IsExperimentalAppListEnabled()
-                                ? IDR_ASH_SHELF_ICON_APPLIST
-                                : IDR_ASH_SHELF_ICON_APPLIST_CLASSIC;
-  const gfx::ImageSkia* forground_image =
-      rb.GetImageNamed(foreground_image_id).ToImageSkia();
+
+  const gfx::ImageSkia& foreground_image =
+      gfx::CreateVectorIcon(gfx::VectorIconId::SEARCH,
+                            kLauncherIconSize, kLauncherIconColor);
 
   gfx::Rect contents_bounds = GetContentsBounds();
-  gfx::Rect background_bounds, forground_bounds;
+  gfx::Rect background_bounds, foreground_bounds;
 
   wm::ShelfAlignment alignment = shelf_view_->shelf()->alignment();
   background_bounds.set_size(background_image->size());
@@ -140,20 +150,20 @@ void AppListButton::OnPaint(gfx::Canvas* canvas) {
         (contents_bounds.width() - background_image->width()) / 2);
   }
 
-  forground_bounds.set_size(forground_image->size());
-  forground_bounds.set_x(background_bounds.x() +
+  foreground_bounds.set_size(foreground_image.size());
+  foreground_bounds.set_x(background_bounds.x() +
       std::max(0,
-          (background_bounds.width() - forground_bounds.width()) / 2));
-  forground_bounds.set_y(background_bounds.y() +
+          (background_bounds.width() - foreground_bounds.width()) / 2));
+  foreground_bounds.set_y(background_bounds.y() +
       std::max(0,
-          (background_bounds.height() - forground_bounds.height()) / 2));
+          (background_bounds.height() - foreground_bounds.height()) / 2));
 
   canvas->DrawImageInt(*background_image,
                        background_bounds.x(),
                        background_bounds.y());
-  canvas->DrawImageInt(*forground_image,
-                       forground_bounds.x(),
-                       forground_bounds.y());
+  canvas->DrawImageInt(foreground_image,
+                       foreground_bounds.x(),
+                       foreground_bounds.y());
 
   views::Painter::PaintFocusPainter(this, canvas, focus_painter());
 }