Move ownership of PowerSaveBlocker from WakeLockServiceContext to WakeLockServiceImpl

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index b4ac5c96864391a7ee595cda8f85ebe9f9d587f8..0af120f3740c9e55cfe291db6dde530578f6512f 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -44,6 +44,12 @@ namespace blink {
 struct WebFindOptions;
 }
 
+namespace device {
+namespace mojom {
+class WakeLockContext;
+}
+}
+
 namespace net {
 struct LoadStateWithParam;
 }
@@ -661,6 +667,9 @@ class WebContents : public PageNavigator,
   // otherwise.
   virtual WebContents* GetOriginalOpener() const = 0;
 
+  // Returns the WakeLockContext accociated with this WebContents.
+  virtual device::mojom::WakeLockContext* GetWakeLockContext() = 0;
+
   typedef base::Callback<void(
       int, /* id */
       int, /* HTTP status code */