Move ownership of PowerSaveBlocker from WakeLockServiceContext to WakeLockServiceImpl

device/wake_lock/wake_lock_service_impl.cc

 // 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.
 
 #include "device/wake_lock/wake_lock_service_impl.h"
 
 #include <utility>
 
-#include "device/wake_lock/wake_lock_service_context.h"
+#include "base/memory/ptr_util.h"
 
 namespace device {
 
-WakeLockServiceImpl::WakeLockServiceImpl(WakeLockServiceContext* context)
-    : context_(context), wake_lock_request_outstanding_(false) {}
+WakeLockServiceImpl::WakeLockServiceImpl(
+    mojom::WakeLockServiceRequest request,
+    device::PowerSaveBlocker::PowerSaveBlockerType type,
+    device::PowerSaveBlocker::Reason reason,
+    const std::string& description,
+    int context_id,
+    WakeLockContextCallback native_view_getter,
+    scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
+    : type_(type),
+      reason_(reason),
+      description_(base::MakeUnique<std::string>(description)),
+      num_lock_requests_(0),
+#if defined(OS_ANDROID)
+      context_id_(context_id),
+      native_view_getter_(native_view_getter),
+#endif
+      main_task_runner_(base::ThreadTaskRunnerHandle::Get()),
+      file_task_runner_(std::move(file_task_runner)) {
+  AddClient(std::move(request));
+  binding_set_.set_connection_error_handler(base::Bind(
+      &WakeLockServiceImpl::OnConnectionError, base::Unretained(this)));
+}
 
-WakeLockServiceImpl::~WakeLockServiceImpl() {
-  CancelWakeLock();
+WakeLockServiceImpl::~WakeLockServiceImpl() {}
+
+void WakeLockServiceImpl::AddClient(mojom::WakeLockServiceRequest request) {
+  binding_set_.AddBinding(this, std::move(request),
+                          base::MakeUnique<bool>(false));
 }
 
 void WakeLockServiceImpl::RequestWakeLock() {
-  if (wake_lock_request_outstanding_)
+  DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(binding_set_.dispatch_context());
+
+  // Uses the Context to get the outstanding status of current binding.
+  // Two consecutive requests from the same client should be coalesced
+  // as one request.
+  if (*binding_set_.dispatch_context())
     return;
 
-  wake_lock_request_outstanding_ = true;
-  context_->RequestWakeLock();
+  *binding_set_.dispatch_context() = true;
+  num_lock_requests_++;
+  UpdateWakeLock();
 }
 
 void WakeLockServiceImpl::CancelWakeLock() {
-  if (!wake_lock_request_outstanding_)
+  DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(binding_set_.dispatch_context());
+
+  if (!(*binding_set_.dispatch_context()))
     return;
 
-  wake_lock_request_outstanding_ = false;
-  context_->CancelWakeLock();
+  *binding_set_.dispatch_context() = false;
+  if (num_lock_requests_ > 0) {

[blundell, 2017/05/09 08:22:44]

This can be a DCHECK instead of an if statement, right? You've just verified
above that at least one client (this one) has an outstanding request.

+    num_lock_requests_--;
+    UpdateWakeLock();
+  }
+}
+
+void WakeLockServiceImpl::HasWakeLockForTests(
+    const HasWakeLockForTestsCallback& callback) {
+  callback.Run(!!wake_lock_);
+}
+void WakeLockServiceImpl::UpdateWakeLock() {
+  DCHECK(num_lock_requests_ >= 0);
+
+  if (num_lock_requests_) {
+    if (!wake_lock_)
+      CreateWakeLock();
+  } else {
+    if (wake_lock_)
+      RemoveWakeLock();
+  }
+}
+
+void WakeLockServiceImpl::CreateWakeLock() {
+  DCHECK(!wake_lock_);
+
+  if (type_ != device::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep ||
+      reason_ != device::PowerSaveBlocker::kReasonOther ||
+      *description_ != "Wake Lock API") {
+    // TODO(ke.he@intel.com): Fully generalize the WakeLock interface and impl.
+    NOTREACHED();
+    return;
+  }
+
+  wake_lock_ = base::MakeUnique<device::PowerSaveBlocker>(
+      type_, reason_, *description_, main_task_runner_, file_task_runner_);
+
+#if defined(OS_ANDROID)
+  gfx::NativeView native_view = native_view_getter_.Run(context_id_);
+  if (native_view)
+    wake_lock_.get()->InitDisplaySleepBlocker(native_view);
+#endif
+}
+
+void WakeLockServiceImpl::RemoveWakeLock() {
+  DCHECK(wake_lock_);
+  wake_lock_.reset();
+}
+
+void WakeLockServiceImpl::OnConnectionError() {
+  DCHECK(binding_set_.dispatch_context());

[blundell, 2017/05/09 08:22:44]

We don't need this: It's a basic property of BindingSet that this DCHECK will be
true here, and the proper place to check it would be in tests of BindingSet
itself. I think it's more confusing to the reader to have it here than not.

+
+  // If the error-happening client's wakelock is in outstanding status,
+  // decrease the num_lock_requests and call UpdateWakeLock().
+  if (*binding_set_.dispatch_context() && num_lock_requests_ > 0) {
+    num_lock_requests_--;
+    UpdateWakeLock();
+  }
+
+  // If |binding_set_| is empty, WakeLockServiceImpl should delele itself.

[blundell, 2017/05/09 08:22:44]

delete

+  if (binding_set_.empty())
+    base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this);
 }
 
 }  // namespace device