Push API: Don't require notification if tab is visible.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 0f56ad43aae40943a046046fdf34f6b9341d1974..f14506d7b5e21a93b423788fbd3058b6f160ae16 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -180,7 +180,9 @@ class CONTENT_EXPORT WebContentsImpl
     return screen_orientation_dispatcher_host_.get();
   }
 
-  bool should_normally_be_visible() { return should_normally_be_visible_; }
+  bool should_normally_be_visible() const {
+    return should_normally_be_visible_;
+  }
 
   // Indicate if the window has been occluded, and pass this to the views, only
   // if there is no active capture going on (otherwise it is dropped on the