Move ownership of PowerSaveBlocker from WakeLockServiceContext to WakeLockServiceImpl

content/browser/web_contents/web_contents_impl.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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 2587 matching lines @@
     return nullptr;
 
   return guest->GetMainFrame();
 }
 
 device::GeolocationServiceContext*
 WebContentsImpl::GetGeolocationServiceContext() {
   return geolocation_service_context_.get();
 }
 
-device::mojom::WakeLockContext* WebContentsImpl::GetWakeLockServiceContext() {
+device::mojom::WakeLockContext* WebContentsImpl::GetWakeLockContext() {
   if (!wake_lock_context_host_)
     wake_lock_context_host_.reset(new WakeLockContextHost(this));
   return wake_lock_context_host_->GetWakeLockContext();
 }
 
+device::mojom::WakeLockService* WebContentsImpl::GetRendererWakeLock() {
+  // WebContents creates a long-lived connection to one WakeLockServiceImpl.
+  // All the frames' requests will be added into the BindingSet of
+  // WakeLockServiceImpl via this connection.
+  if (!renderer_wake_lock_) {
+    device::mojom::WakeLockContext* wake_lock_context = GetWakeLockContext();
+    if (!wake_lock_context) {

[blundell, 2017/05/04 15:40:50]

will this ever happen?

[ke.he, 2017/05/05 08:58:00]

Yes, in
https://cs.chromium.org/chromium/src/content/browser/wake_lock/wake_lock_cont...
There is a condition "if (ServiceManagerConnection::GetForProcess())" that
possibly skip executing "mojo::MakeRequest(&wake_lock_context_)"

+      return nullptr;
+    }
+    wake_lock_context->GetWakeLock(mojo::MakeRequest(&renderer_wake_lock_));
+  }
+  return renderer_wake_lock_.get();
+}
+
 void WebContentsImpl::OnShowValidationMessage(
     RenderViewHostImpl* source,
     const gfx::Rect& anchor_in_root_view,
     const base::string16& main_text,
     const base::string16& sub_text) {
   // TODO(nick): Should we consider |source| here or pass it to the delegate?
   if (delegate_)
     delegate_->ShowValidationMessage(
         this, anchor_in_root_view, main_text, sub_text);
 }
@@ skipping 2961 matching lines @@
     RenderViewHost* render_view_host = RenderViewHost::From(render_widget_host);
     if (!render_view_host)
       continue;
     render_view_host_set.insert(render_view_host);
   }
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 }  // namespace content