Move ownership of PowerSaveBlocker from WakeLockServiceContext to WakeLockServiceImpl

device/wake_lock/public/interfaces/wake_lock_context.mojom

 // Copyright 2015 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.
 
 module device.mojom;
 
 import "device/wake_lock/public/interfaces/wake_lock_service.mojom";
 
+// TODO(heke): Switch PowerSaveBlocker to use WakeLockType and WakeLockReason
+// below once it has no direct consumers.
+enum WakeLockType {
+    // Prevent the application from being suspended. On some platforms, apps may
+    // be suspended when they are not visible to the user. This type of block
+    // requests that the app continue to run in that case, and on all platforms
+    // prevents the system from sleeping.
+    // Example use cases: downloading a file, playing audio.
+    PreventAppSuspension = 0,
+
+    // Prevent the display from going to sleep. This also has the side effect of
+    // preventing the system from sleeping, but does not necessarily prevent the
+    // app from being suspended on some platforms if the user hides it.
+    // Example use case: playing video.
+    PreventDisplaySleep = 1,
+};
+
+enum WakeLockReason {
+    // Audio is being played.
+    ReasonAudioPlayback = 0,
+    // Video is being played.
+    ReasonVideoPlayback = 1,
+    // WakeLock for some other reason.
+    ReasonOther = 2,
+};
+
 // Context in which WakeLockService instances operate.
 interface WakeLockContext {
   // Gets a WakeLockService within this context.
-  GetWakeLock(WakeLockService& wake_lock);
+  GetWakeLock(WakeLockType type, WakeLockReason reason, string description, WakeLockService& wake_lock);
 
   // Test-only method that returns whethere a wake lock is currently active
   // within this context.
   HasWakeLockForTests() => (bool result);
 };