Don't use blur when maximized

Also use NOT_DRAWN layer for shelf because it has no real content.
All child views have its own layers.

This also chagnes the opacity to 100% per discussion with sgabriel@

Bug: 899079
Test: manual. No
Change-Id: I6ea82784e49e929902a7a7d00fc934d9c8033045
Reviewed-on: https://chromium-review.googlesource.com/c/1300108Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602942}

ash/shelf/shelf_constants.h

@@ -69,7 +69,7 @@ ASH_EXPORT constexpr SkColor kShelfIconColor = SK_ColorWHITE;
 // The alpha value for the shelf background.
 ASH_EXPORT constexpr int kShelfTranslucentOverAppList = 51;            // 20%
 ASH_EXPORT constexpr int kShelfTranslucentAlpha = 153;                 // 60%
-ASH_EXPORT constexpr int kShelfTranslucentMaximizedWindow = 230;       // 90%
+ASH_EXPORT constexpr int kShelfTranslucentMaximizedWindow = 255;       // 100%
 
 // The alpha value used to darken a colorized shelf when the shelf is
 // translucent.

ash/shelf/shelf_layout_manager.cc

@@ -1173,9 +1173,10 @@ bool ShelfLayoutManager::IsShelfAutoHideForFullscreenMaximized() const {
 }
 
 bool ShelfLayoutManager::ShouldBlurShelfBackground() {
-  if (!IsBackgroundBlurEnabled())
-    return false;
-  return state_.session_state == session_manager::SessionState::ACTIVE;
+  return IsBackgroundBlurEnabled() &&
+         (shelf_background_type_ == SHELF_BACKGROUND_DEFAULT ||
+          shelf_background_type_ == SHELF_BACKGROUND_OVERLAP) &&
+         state_.session_state == session_manager::SessionState::ACTIVE;
 }
 
 ////////////////////////////////////////////////////////////////////////////////

ash/shelf/shelf_widget.cc

@@ -289,7 +289,7 @@ ShelfWidget::ShelfWidget(aura::Window* shelf_container, Shelf* shelf)
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.name = "ShelfWidget";
-  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
+  params.layer_type = ui::LAYER_NOT_DRAWN;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.delegate = delegate_view_;
   params.parent = shelf_container;