Wake Lock API implementation (Chromium part)

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index a25fc594cd3861f74bc23bc863bab09ffe8255a5..59f7d124182d8a77044199149b0c88fd87927bb7 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -41,6 +41,7 @@
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
+#include "content/browser/wake_lock/wake_lock_service_context.h"
 #include "content/common/accessibility_messages.h"
 #include "content/common/frame_messages.h"
 #include "content/common/input_messages.h"
@@ -1590,6 +1591,22 @@ void RenderFrameHostImpl::RegisterMojoServices() {
                               base::Unretained(this))));
   }
 
+  WakeLockServiceContext* wake_lock_service_context =
+      delegate_ ? delegate_->GetWakeLockServiceContext() : nullptr;
+  if (wake_lock_service_context) {
+    // WakeLockServiceContext is owned by WebContentsImpl so it will outlive
+    // this RenderFrameHostImpl, hence a raw pointer can be bound to service
+    // factory callback.
+    // WakeLockServiceContext uses RenderFrameHost pointers as opaque frame
+    // identifiers and never dereferences them, so it is safe to pass raw
+    // RenderFrameHost pointers. Additionally, WakeLockServiceContext observes

[nasko, 2015/09/03 17:53:37]

This comment is good, but the intention doesn't seem right. If we need an unique
identifier for a frame, there is already that on FrameTreeNode. If you need
unique identifier on the RFH, we also have that - process id, RFH id.
I think using one of these will be much more appropriate than using a pointer
value, especially when the address can be reallocated based on the memory
allocator behavior.

[alogvinov, 2015/09/04 15:39:25]

Switched to using FrameTreeNode ids.

+    // frame removal so it doesn't keep stale frame pointers.
+    GetServiceRegistry()->AddService<WakeLockService>(
+        base::Bind(&WakeLockServiceContext::CreateService,
+                   base::Unretained(wake_lock_service_context),
+                   base::Unretained(this)));
+  }
+
   if (!permission_service_context_)
     permission_service_context_.reset(new PermissionServiceContext(this));