Add a battery icon to the right of Tether networks in system tray.

ash/system/network/network_list.cc

Index: ash/system/network/network_list.cc
diff --git a/ash/system/network/network_list.cc b/ash/system/network/network_list.cc
index 5415eabb3c6d5b5315992a82b241e91250cb3815..9e48c9f257855c2b3073f524cdae60977cc021a1 100644
--- a/ash/system/network/network_list.cc
+++ b/ash/system/network/network_list.cc
@@ -6,6 +6,7 @@
 
 #include <memory>
 
+#include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/strings/grit/ash_strings.h"
@@ -22,6 +23,7 @@
 #include "ash/system/tray/tray_popup_item_style.h"
 #include "ash/system/tray/tray_popup_utils.h"
 #include "ash/system/tray/tri_view.h"
+#include "base/i18n/number_formatting.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
@@ -35,6 +37,7 @@
 #include "third_party/cros_system_api/dbus/service_constants.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ -577,9 +580,56 @@ void NetworkListView::UpdateViewForNetwork(HoverHighlightView* view,
   else if (info.connecting)
     SetupConnectingScrollListItem(view);
   view->SetTooltipText(info.tooltip);
-  views::View* controlled_icon = CreateControlledByExtensionView(info);
-  if (controlled_icon)
-    view->AddRightView(controlled_icon);
+  views::View* power_icon = CreatePowerStatusView(info);
+  if (power_icon) {
+    view->AddRightView(power_icon);
+  } else {
+    views::View* controlled_icon = CreateControlledByExtensionView(info);
+    if (controlled_icon)
+      view->AddRightView(controlled_icon);
+  }
+}
+
+views::View* NetworkListView::CreatePowerStatusView(const NetworkInfo& info) {
+  // Mobile can be Cellular or Tether.
+  if (info.type != NetworkInfo::Type::MOBILE)
+    return nullptr;
+
+  NetworkStateHandler* handler = NetworkHandler::Get()->network_state_handler();

[stevenjb, 2017/06/12 16:20:51]

handler is only used once, so no need for local.

[lesliewatkins, 2017/06/12 16:53:34]

Done.

+  const chromeos::NetworkState* network =
+      handler->GetNetworkStateFromGuid(info.guid);
+
+  // Only return a battery icon for Tether network type.
+  if (NetworkTypePattern::Tether().MatchesType(network->type())) {

[stevenjb, 2017/06/12 16:20:51]

invert and early exit

[lesliewatkins, 2017/06/12 16:53:35]

Done.

+    views::ImageView* right_icon = TrayPopupUtils::CreateMainImageView();

[stevenjb, 2017/06/12 16:20:51]

Why 'right_icon'?

[lesliewatkins, 2017/06/12 16:53:35]

A holdover from before the icon creation was in its own function. I changed the
name to 'icon'.

+    int canvas_size = gfx::Size(kMenuIconSize, kMenuIconSize);
+    gfx::Canvas canvas(canvas_size, 1.0f, false /* opaque */);
+
+    // Paint the battery's base (background) color.
+    PaintVectorIcon(&canvas, kSystemTrayBatteryIcon, kMenuIconSize,
+                    kMenuIconColorDisabled);
+    // Paint the charged portion of the battery.
+    const int charge_height =
+        network->battery_percentage() * kMenuIconSize / 100;
+    gfx::Rect clip_rect(0, kBatteryCanvasSize - charge_height,
+                        kMenuIconSize charge_height);
+    canvas.Save();
+    canvas.ClipRect(clip_rect);
+    PaintVectorIcon(&canvas, kSystemTrayBatteryIcon, kMenuIconSize,
+                    kMenuIconColor);
+    canvas.Restore();
+
+    // Show the battery icon with correct charge height.
+    right_icon->SetImage(
+        gfx::ImageSkia::CreateFrom1xBitmap(canvas.GetBitmap()));
+    // Show the numeric battery percentage on hover.
+    right_icon->SetTooltipText(
+        base::FormatPercent(network->battery_percentage()));
+
+    return right_icon;
+  }
+
+  return nullptr;
 }
 
 views::View* NetworkListView::CreateControlledByExtensionView(