Get signals working in the EXTRA_DATA section of MHTML

chrome/browser/android/offline_pages/prerendering_offliner.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/android/offline_pages/prerendering_offliner.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/sys_info.h"
 #include "chrome/browser/android/offline_pages/offline_page_mhtml_archiver.h"
 #include "chrome/browser/android/offline_pages/offliner_helper.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/offline_pages/core/background/offliner_policy.h"
 #include "components/offline_pages/core/background/save_page_request.h"
 #include "components/offline_pages/core/client_namespace_constants.h"
 #include "components/offline_pages/core/downloads/download_ui_adapter.h"
 #include "components/offline_pages/core/offline_page_model.h"
+#include "content/browser/download/mhtml_extra_data.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/web_contents.h"
 
 namespace offline_pages {
 
 PrerenderingOffliner::PrerenderingOffliner(
     content::BrowserContext* browser_context,
     const OfflinerPolicy* policy,
     OfflinePageModel* offline_page_model)
     : browser_context_(browser_context),
@@ skipping 48 matching lines @@
     save_page_params.client_id = request.client_id();
     save_page_params.proposed_offline_id = request.request_id();
     save_page_params.is_background = true;
     // Pass in the original URL if it is different from the last committed URL
     // when redirects occur.
     if (!request.original_url().is_empty())
       save_page_params.original_url = request.original_url();
     else if (save_page_params.url != request.url())
       save_page_params.original_url = request.url();
 
+    // Write the signal data into a single string.
+    const char kContentTypeLine[] = "Content-Type: application/json\r\n";
+    std::string signal_string(kContentTypeLine);
+    const std::vector<std::string>& signals = loader_->GetSignalData();
+
+    // TODO(petewil): Convert this to JSON.
+    for (std::string signal : signals) {
+      signal_string += signal;
+      signal_string += "\r\n";
+    }
+
+    // Attach the signal data to the web contents.
+    web_contents->SetUserData(content::kMHTMLExtraDataKey,
+                              std::unique_ptr<base::SupportsUserData::Data>(
+                                  new content::MHTMLExtraData(signal_string)));
+
     SavePage(save_page_params, std::move(archiver),
              base::Bind(&PrerenderingOffliner::OnSavePageDone,
                         weak_ptr_factory_.GetWeakPtr(), request));
   } else {
     // Clear pending request and app listener then run completion callback.
     pending_request_.reset(nullptr);
     app_listener_.reset(nullptr);
     completion_callback_.Run(request, load_status);
   }
 }
@@ skipping 187 matching lines @@
 void PrerenderingOffliner::HandleApplicationStateChangeCancel(
     const SavePageRequest& request,
     int64_t offline_id) {
   // This shouldn't be immediate, but account for case where request was reset
   // while waiting for callback.
   if (pending_request_ && pending_request_->request_id() != offline_id)
     return;
   completion_callback_.Run(request, RequestStatus::FOREGROUND_CANCELED);
 }
 }  // namespace offline_pages