Move ownership of PowerSaveBlocker from WakeLockServiceContext to WakeLockServiceImpl

device/wake_lock/wake_lock_service_context.h

Index: device/wake_lock/wake_lock_service_context.h
diff --git a/device/wake_lock/wake_lock_service_context.h b/device/wake_lock/wake_lock_service_context.h
index 0baa1a79c394dfe79c5f460ba35fdf2da2533dbf..991b6e1301775e31605fe0600f6f3a0fa0afab1f 100644
--- a/device/wake_lock/wake_lock_service_context.h
+++ b/device/wake_lock/wake_lock_service_context.h
@@ -16,7 +16,6 @@
 #include "device/wake_lock/public/interfaces/wake_lock_context.mojom.h"
 #include "device/wake_lock/wake_lock_service_impl.h"
 #include "mojo/public/cpp/bindings/binding.h"
-#include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/public/cpp/bindings/strong_binding_set.h"
 #include "ui/gfx/native_widget_types.h"
 
@@ -49,38 +48,28 @@ class WakeLockServiceContext : public mojom::WakeLockContext {
   ~WakeLockServiceContext() override;
 
   // mojom::WakeLockContext:
-  void GetWakeLock(
-      mojo::InterfaceRequest<mojom::WakeLockService> request) override;
+  void GetWakeLock(device::PowerSaveBlocker::PowerSaveBlockerType type,
+                   device::PowerSaveBlocker::Reason reason,
+                   const std::string& description,
+                   mojom::WakeLockServiceRequest request) override;
   void HasWakeLockForTests(

[blundell, 2017/05/02 11:27:43]

IIUC, the only reason that this class still has any complexity is because of
this method. Let's move this method into WakeLockService; the browsertest can
access it by accessing the WebContent's |blink_wake_lock_|. Then this class
(i.e., WakeLockServiceContext) becomes dead-simple: it just has a StrongBinding
to its request, it doesn't need to track the WakeLockServiceImpls at all;
WakeLockServiceImpl can instead have a BindingSet to manage all its requests and
delete itself when that binding set becomes empty.

[ke.he, 2017/05/04 11:54:14]

Done.

       const HasWakeLockForTestsCallback& callback) override;
-
-  // Requests wake lock.
-  void RequestWakeLock();
-
-  // Cancels pending wake lock request.
-  void CancelWakeLock();
+  void IncreaseWakeLockCount();
+  void DecreaseWakeLockCount();
 
  private:
-  void CreateWakeLock();
-  void RemoveWakeLock();
-  void UpdateWakeLock();
   void OnContextBindingError();
 
   // Checks whether this instance is still needed, and if not, destroys it.
   void DestroyIfNoLongerNeeded();
 
-  scoped_refptr<base::SequencedTaskRunner> main_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
 
-  int num_lock_requests_;
-
-  // The actual power save blocker for screen.
-  std::unique_ptr<PowerSaveBlocker> wake_lock_;
+  // Counts number of wake lock instances, for test usage.
+  int wake_lock_count_;
 
-#if defined(OS_ANDROID)
   int context_id_;
   WakeLockContextCallback native_view_getter_;
-#endif
 
   mojo::Binding<mojom::WakeLockContext> context_binding_;
   bool context_binding_encountered_error_;