Make UnifiedSystemTray background semi-transparent

According to UnifiedSystemTray spec, the tray has blurry background.

It is appropriate to use app_list::IsBackgroundBlurEnabled, becuase
app_list is moving from ui/app_list to ash/app_list (go/move-applist),
and also it returns true only on high-end devices which have small
performance impact when the blur is enabled.

Screenshot: http://screen/wUryXYd800Y
Design doc: go/cros-qs-restyling

TEST=out/Release/chrome
--enable-features=EnableBackgroundBlur,SystenTrayUnified
BUG=811641

Change-Id: I270751b734110023261bdb698af33b31fb1af87f
Reviewed-on: https://chromium-review.googlesource.com/970055Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544313}

ash/system/tray/tray_constants.h

@@ -127,6 +127,9 @@ extern const int kTrayPopupSystemInfoRowHeight;
 
 // The colors used when --enable-features=SystemTrayUnified flag is enabled.
 constexpr SkColor kUnifiedMenuBackgroundColor = SkColorSetRGB(0x20, 0x21, 0x24);
+constexpr SkColor kUnifiedMenuBackgroundColorWithBlur =
+    SkColorSetA(kUnifiedMenuBackgroundColor, 0xB3);
+constexpr float kUnifiedMenuBackgroundBlur = 30.f;
 constexpr SkColor kUnifiedMenuTextColor = SkColorSetRGB(0xf1, 0xf2, 0xf3);
 constexpr SkColor kUnifiedMenuIconColor = SkColorSetRGB(0xf1, 0xf2, 0xf3);
 constexpr SkColor kUnifiedMenuSecondaryTextColor =

ash/system/unified/feature_pod_button.cc

@@ -27,6 +27,7 @@ void ConfigureFeaturePodLabel(views::Label* label) {
   label->SetMultiLine(true);
   label->SizeToFit(kUnifiedFeaturePodSize.width());
   label->SetHorizontalAlignment(gfx::ALIGN_CENTER);
+  label->SetSubpixelRenderingEnabled(false);
 }
 
 }  // namespace

ash/system/unified/sign_out_button.cc

@@ -30,6 +30,7 @@ SignOutButton::SignOutButton(views::ButtonListener* listener)
   SetEnabledTextColors(kUnifiedMenuTextColor);
   SetHorizontalAlignment(gfx::ALIGN_CENTER);
   SetBorder(views::CreateEmptyBorder(gfx::Insets()));
+  label()->SetSubpixelRenderingEnabled(false);
   TrayPopupUtils::ConfigureTrayPopupButton(this);
 }
 

ash/system/unified/unified_system_info_view.cc

@@ -66,6 +66,7 @@ DateView::DateView() : label_(new views::Label) {
   AddChildView(label_);
 
   label_->SetAutoColorReadabilityEnabled(false);
+  label_->SetSubpixelRenderingEnabled(false);
   label_->SetEnabledColor(kUnifiedMenuTextColor);
   Update();
 
@@ -174,6 +175,7 @@ void BatteryView::Update() {
 
 void BatteryView::ConfigureLabel(views::Label* label) {
   label->SetAutoColorReadabilityEnabled(false);
+  label->SetSubpixelRenderingEnabled(false);
   label->SetEnabledColor(kUnifiedMenuSecondaryTextColor);
 }
 
@@ -207,6 +209,7 @@ EnterpriseManagedView::EnterpriseManagedView() {
 
   auto* label = new views::Label;
   label->SetAutoColorReadabilityEnabled(false);
+  label->SetSubpixelRenderingEnabled(false);
   label->SetEnabledColor(kUnifiedMenuSecondaryTextColor);
   label->SetText(
       l10n_util::GetStringUTF16(IDS_ASH_ENTERPRISE_DEVICE_MANAGED_SHORT));

ash/system/unified/unified_system_tray_bubble.cc

@@ -9,6 +9,7 @@
 #include "ash/system/unified/unified_system_tray.h"
 #include "ash/system/unified/unified_system_tray_controller.h"
 #include "ash/system/unified/unified_system_tray_view.h"
+#include "ui/app_list/app_list_features.h"
 
 namespace ash {
 
@@ -29,13 +30,19 @@ UnifiedSystemTrayBubble::UnifiedSystemTrayBubble(UnifiedSystemTray* tray)
   bubble_view->AddChildView(controller_->CreateView());
   bubble_view->set_anchor_view_insets(
       tray->shelf()->GetSystemTrayAnchor()->GetBubbleAnchorInsets());
-  bubble_view->set_color(kUnifiedMenuBackgroundColor);
+  bubble_view->set_color(SK_ColorTRANSPARENT);
+  bubble_view->layer()->SetFillsBoundsOpaquely(false);
 
   bubble_widget_ = views::BubbleDialogDelegateView::CreateBubble(bubble_view);
   bubble_widget_->AddObserver(this);
 
   TrayBackgroundView::InitializeBubbleAnimations(bubble_widget_);
   bubble_view->InitializeAndShowBubble();
+  if (app_list::features::IsBackgroundBlurEnabled()) {
+    // ClientView's layer (See TrayBubbleView::InitializeAndShowBubble())
+    bubble_view->layer()->parent()->SetBackgroundBlur(
+        kUnifiedMenuBackgroundBlur);
+  }
 
   bubble_widget_->widget_delegate()->set_can_activate(true);
   bubble_widget_->Activate();

ash/system/unified/unified_system_tray_view.cc

@@ -4,10 +4,13 @@
 
 #include "ash/system/unified/unified_system_tray_view.h"
 
+#include "ash/system/tray/tray_constants.h"
 #include "ash/system/unified/feature_pod_button.h"
 #include "ash/system/unified/feature_pods_container_view.h"
 #include "ash/system/unified/top_shortcuts_view.h"
 #include "ash/system/unified/unified_system_info_view.h"
+#include "ui/app_list/app_list_features.h"
+#include "ui/views/background.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace ash {
@@ -22,6 +25,13 @@ UnifiedSystemTrayView::UnifiedSystemTrayView(
   SetLayoutManager(
       std::make_unique<views::BoxLayout>(views::BoxLayout::kVertical));
 
+  SetBackground(
+      views::CreateSolidBackground(app_list::features::IsBackgroundBlurEnabled()
+                                       ? kUnifiedMenuBackgroundColorWithBlur
+                                       : kUnifiedMenuBackgroundColor));
+  SetPaintToLayer();
+  layer()->SetFillsBoundsOpaquely(false);
+
   AddChildView(new TopShortcutsView(controller_));
   AddChildView(feature_pods_container_);
   AddChildView(system_info_view_);