Adding DRP specfic UMA for FirstContentfulPaint

content/browser/frame_host/navigation_request.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/browser/frame_host/navigation_entry_impl.h"
 #include "content/browser/loader/navigation_url_loader_delegate.h"
 #include "content/common/content_export.h"
 #include "content/common/frame_message_enums.h"
 #include "content/common/navigation_params.h"
 #include "content/public/browser/navigation_throttle.h"
 
 namespace content {
 
 class FrameNavigationEntry;
 class FrameTreeNode;
 class NavigationControllerImpl;
 class NavigationHandleImpl;
 class NavigationURLLoader;
+class NavigationData;
 class NavigatorDelegate;
 class ResourceRequestBody;
 class SiteInstanceImpl;
+class StreamHandle;

[nasko, 2016/05/09 17:35:43]

Why is this needed? How did the file compile before it?

[RyanSturm, 2016/05/09 18:27:31]

navigation_url_loader_delegate.h is one header that also forward declares this
class. If that file ever didn't need to forward declare StreamHandle anymore, it
would be weird to have a compiler error on building this. Leaving it for now,
but I'll remove it if it seems out of scope of this CL.

 struct NavigationRequestInfo;
 
 // PlzNavigate
 // A UI thread object that owns a navigation request until it commits. It
 // ensures the UI thread can start a navigation request in the
 // ResourceDispatcherHost (that lives on the IO thread).
 // TODO(clamy): Describe the interactions between the UI and IO thread during
 // the navigation following its refactoring.
 class CONTENT_EXPORT NavigationRequest : public NavigationURLLoaderDelegate {
  public:
@@ skipping 127 matching lines @@
                     const RequestNavigationParams& request_params,
                     scoped_refptr<ResourceRequestBody> body,
                     bool browser_initiated,
                     const FrameNavigationEntry* frame_navigation_entry,
                     const NavigationEntryImpl* navitation_entry);
 
   // NavigationURLLoaderDelegate implementation.
   void OnRequestRedirected(
       const net::RedirectInfo& redirect_info,
       const scoped_refptr<ResourceResponse>& response) override;
-  void OnResponseStarted(const scoped_refptr<ResourceResponse>& response,
-                         std::unique_ptr<StreamHandle> body) override;
+  void OnResponseStarted(
+      const scoped_refptr<ResourceResponse>& response,
+      std::unique_ptr<StreamHandle> body,
+      std::unique_ptr<const NavigationData> navigation_data) override;

[nasko, 2016/05/09 17:35:43]

Why do we need const here? content/ can't really change anything within this
object, as the interface is pretty much empty.

[RyanSturm, 2016/05/09 18:27:31]

Agreed. this was a constraint of trying to clarify that content won't change it,
but the embedder might choose to change it later anyway.

   void OnRequestFailed(bool has_stale_copy_in_cache, int net_error) override;
   void OnRequestStarted(base::TimeTicks timestamp) override;
 
   // Called when the NavigationThrottles have been checked by the
   // NavigationHandle.
   void OnStartChecksComplete(NavigationThrottle::ThrottleCheckResult result);
   void OnRedirectChecksComplete(NavigationThrottle::ThrottleCheckResult result);
   void OnWillProcessResponseChecksComplete(
       NavigationThrottle::ThrottleCheckResult result);
 
@@ skipping 47 matching lines @@
   // the WillProcessResponse checks are performed by the NavigationHandle.
   scoped_refptr<ResourceResponse> response_;
   std::unique_ptr<StreamHandle> body_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationRequest);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATION_REQUEST_H_