Send navigation_start to the browser in DidStartProvisionalLoad IPC

content/browser/frame_host/navigation_handle_impl.h

Index: content/browser/frame_host/navigation_handle_impl.h
diff --git a/content/browser/frame_host/navigation_handle_impl.h b/content/browser/frame_host/navigation_handle_impl.h
index 6f46707108e531ceac132639638d387611e5710f..811d09cc044d2daabb73217f0645fafa2c6179d6 100644
--- a/content/browser/frame_host/navigation_handle_impl.h
+++ b/content/browser/frame_host/navigation_handle_impl.h
@@ -59,12 +59,14 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
  public:
   static scoped_ptr<NavigationHandleImpl> Create(
       const GURL& url,
-      FrameTreeNode* frame_tree_node);
+      FrameTreeNode* frame_tree_node,
+      const base::TimeTicks& navigation_start);
   ~NavigationHandleImpl() override;
 
   // NavigationHandle implementation:
   const GURL& GetURL() override;
   bool IsInMainFrame() override;
+  const base::TimeTicks& GetNavigationStart() override;
   bool IsPost() override;
   const Referrer& GetReferrer() override;
   bool HasUserGesture() override;
@@ -161,8 +163,13 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
     DID_COMMIT_ERROR_PAGE,
   };
 
+  // |navigation_start| comes from the DidStartProvisionalLoad IPC, which tracks
+  // both renderer-initiated and browser-initiated navigation start.
+  // PlzNavigate: This value always comes from the CommonNavigationParams
+  // associated with this navigation.
   NavigationHandleImpl(const GURL& url,
-                       FrameTreeNode* frame_tree_node);
+                       FrameTreeNode* frame_tree_node,
+                       const base::TimeTicks& navigation_start);
 
   NavigationThrottle::ThrottleCheckResult CheckWillStartRequest();
   NavigationThrottle::ThrottleCheckResult CheckWillRedirectRequest();
@@ -197,6 +204,9 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
   // The index of the next throttle to check.
   size_t next_index_;
 
+  // The time this navigation started.
+  const base::TimeTicks navigation_start_;
+
   // This callback will be run when all throttle checks have been performed.
   ThrottleChecksFinishedCallback complete_callback_;