Change PowerStatus::GetBatteryImage to not use ExtractImageRep and scale

ash/common/system/chromeos/power/tray_power.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/chromeos/power/tray_power.h"
 
 #include <utility>
 
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/ash_switches.h"
 #include "ash/common/system/chromeos/devicetype_utils.h"
 #include "ash/common/system/chromeos/power/battery_notification.h"
 #include "ash/common/system/chromeos/power/dual_role_notification.h"
 #include "ash/common/system/date/date_view.h"
 #include "ash/common/system/system_notifier.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_item_view.h"
 #include "ash/common/system/tray/tray_utils.h"
 #include "ash/resources/grit/ash_resources.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image_skia_source.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification.h"
 #include "ui/message_center/notification_delegate.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/view.h"
 
 using message_center::MessageCenter;
 using message_center::Notification;
 
 namespace ash {
@@ skipping 55 matching lines @@
 // This view is used only for the tray.
 class PowerTrayView : public TrayItemView {
  public:
   explicit PowerTrayView(SystemTrayItem* owner) : TrayItemView(owner) {
     CreateImageView();
     UpdateImage();
   }
 
   ~PowerTrayView() override {}
 
-  // Overriden from views::View.
+  // Overridden from views::View.
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override {
     node_data->SetName(accessible_name_);
     node_data->role = ui::AX_ROLE_BUTTON;
   }
 
   void UpdateStatus(bool battery_alert) {
     UpdateImage();
     SetVisible(PowerStatus::Get()->IsBatteryPresent());
 
     if (battery_alert) {
       accessible_name_ = PowerStatus::Get()->GetAccessibleNameString(true);
       NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
     }
   }
 
  private:
+  class PowerTrayImageSource : public gfx::ImageSkiaSource {
+   public:
+    explicit PowerTrayImageSource(const PowerStatus::BatteryImageInfo& info)
+        : info_(info) {}
+
+    // gfx::ImageSkiaSource implementation.
+    gfx::ImageSkiaRep GetImageForScale(float scale) override {
+      return PowerStatus::Get()->GetBatteryImage(info_, scale);
+    }
+
+    const PowerStatus::BatteryImageInfo& info() const { return info_; }
+
+   private:
+    PowerStatus::BatteryImageInfo info_;
+
+    DISALLOW_COPY_AND_ASSIGN(PowerTrayImageSource);
+  };
+
   void UpdateImage() {
-    const PowerStatus::BatteryImageInfo info =
-        PowerStatus::Get()->GetBatteryImageInfo(PowerStatus::ICON_LIGHT);
-    if (info != previous_image_info_) {
-      image_view()->SetImage(PowerStatus::Get()->GetBatteryImage(info));
-      previous_image_info_ = info;
-    }
+    const PowerStatus::BatteryImageInfo& info =
+        PowerStatus::Get()->GetBatteryImageInfo();
+    // Only change the image when the info changes. http://crbug.com/589348
+    if (image_source_ && image_source_->info() == info)
+      return;
+    image_source_ = new PowerTrayImageSource(info);
+    // gfx::ImageSkia takes ownership of image_source_. It will stay alive until
+    // we call SetImage() again, which only happens here.
+    image_view()->SetImage(
+        gfx::ImageSkia(image_source_, PowerStatus::GetBatteryImageSizeInDip()));
   }
 
   base::string16 accessible_name_;
-
-  // Information about the last-used image. Cached to avoid unnecessary updates
-  // (http://crbug.com/589348).
-  PowerStatus::BatteryImageInfo previous_image_info_;
+  PowerTrayImageSource* image_source_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(PowerTrayView);
 };
 
 }  // namespace tray
 
 const int TrayPower::kCriticalMinutes = 5;
 const int TrayPower::kLowPowerMinutes = 15;
 const int TrayPower::kNoWarningMinutes = 30;
 const int TrayPower::kCriticalPercentage = 5;
@@ skipping 202 matching lines @@
   }
   NOTREACHED();
   return false;
 }
 
 void TrayPower::NotifyUsbNotificationClosedByUser() {
   usb_notification_dismissed_ = true;
 }
 
 }  // namespace ash