Convert NavigationTracingObserver to use the new navigation callbacks.

chrome/browser/tracing/navigation_tracing.h

Index: chrome/browser/tracing/navigation_tracing.h
diff --git a/chrome/browser/tracing/navigation_tracing.h b/chrome/browser/tracing/navigation_tracing.h
index f26287e5185b58fdc667612bb5cbc0f3723bbd61..cfe0e0e5e8db6d438312af71af1556e2e4a43920 100644
--- a/chrome/browser/tracing/navigation_tracing.h
+++ b/chrome/browser/tracing/navigation_tracing.h
@@ -28,12 +28,10 @@ class NavigationTracingObserver
   ~NavigationTracingObserver() override;
 
   // content::WebContentsObserver implementation.
-  void DidStartProvisionalLoadForFrame(
-      content::RenderFrameHost* render_frame_host,
-      const GURL& validated_url,
-      bool is_error_page) override;
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
 
-  static content::BackgroundTracingManager::TriggerHandle navigation_handle;
+  static content::BackgroundTracingManager::TriggerHandle navigation_handle_;

[fmeawad, 2017/01/26 15:44:37]

I think we should rename navigation_handle_ to navigation_trigger_handle_
otherwise the code is harder to read as it would assume that all
navigation_handle* are of the same type.

[jam, 2017/01/26 16:33:35]

Done.

 
   DISALLOW_COPY_AND_ASSIGN(NavigationTracingObserver);
 };