Device Service: Decouple Wake Lock from //content

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 01e7ebef29d1c6df794266af38e405b3ef41176d..a8c4e4b138df49ebc8938f213b312e8734907d6b 100644
--- a/device/wake_lock/wake_lock_service_context.h
+++ b/device/wake_lock/wake_lock_service_context.h
@@ -12,9 +12,10 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
+#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 "ui/gfx/native_widget_types.h"
 
@@ -22,15 +23,26 @@ namespace device {
 
 class PowerSaveBlocker;
 
-class WakeLockServiceContext {
+// Callback that maps a context ID to the NativeView associated with
+// that context. This callback is provided to the Device Service by its
+// embedder.
+using WakeLockContextCallback = base::Callback<gfx::NativeView(int)>;
+
+// Serves requests for WakeLockService connections within a given context.
+class WakeLockServiceContext : public mojom::WakeLockContext {
  public:
   WakeLockServiceContext(
+      mojom::WakeLockContextRequest request,
+      int context_id,
       scoped_refptr<base::SingleThreadTaskRunner> file_task_runner,
-      base::Callback<gfx::NativeView()> native_view_getter);
-  ~WakeLockServiceContext();
+      WakeLockContextCallback native_view_getter);
+  ~WakeLockServiceContext() override;
 
-  // Creates a WakeLockServiceImpl that is strongly bound to |request|.
-  void CreateService(mojo::InterfaceRequest<mojom::WakeLockService> request);
+  // mojom::WakeLockContext:
+  void GetWakeLock(
+      mojo::InterfaceRequest<mojom::WakeLockService> request) override;
+  void HasWakeLockForTests(
+      const HasWakeLockForTestsCallback& callback) override;
 
   // Requests wake lock.
   void RequestWakeLock();
@@ -38,13 +50,11 @@ class WakeLockServiceContext {
   // Cancels pending wake lock request.
   void CancelWakeLock();
 
-  // Used by tests.
-  bool HasWakeLockForTests() const;
-
  private:
   void CreateWakeLock();
   void RemoveWakeLock();
   void UpdateWakeLock();
+  void OnConnectionError();
 
   scoped_refptr<base::SequencedTaskRunner> main_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
@@ -53,9 +63,19 @@ class WakeLockServiceContext {
 
   // The actual power save blocker for screen.
   std::unique_ptr<PowerSaveBlocker> wake_lock_;
-  base::Callback<gfx::NativeView()> native_view_getter_;
 
-  base::WeakPtrFactory<WakeLockServiceContext> weak_factory_;
+  mojo::Binding<mojom::WakeLockContext> binding_;
+
+#if defined(OS_ANDROID)
+  int context_id_;
+  WakeLockContextCallback native_view_getter_;
+#endif
+
+  // The number of connections that the client has in this context,
+  // including both the connection to this implementation and all
+  // connections made via |GetWakeLock()|. When this number reaches
+  // 0 this instance isn't needed anymore and kills itself.
+  int num_connections_;
 
   DISALLOW_COPY_AND_ASSIGN(WakeLockServiceContext);
 };