Support serving offline page by offline ID

chrome/browser/android/offline_pages/offline_page_request_job.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_JOB_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_JOB_H_
 
 #include "base/memory/weak_ptr.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/common/resource_type.h"
 #include "net/url_request/url_request_file_job.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace offline_pages {
 
 // Header that indicates that the offline page should be loaded if it exists
 // regardless current network conditions. Its value is a comma/space separated
 // name-value pair that may provide reason or define custom behavior.
-extern const char kLoadingOfflinePageHeader[];
+extern const char kOfflinePageHeader[];
+// The name used in name-value pair of kLoadingOfflinePageHeader to tell if the

[Dmitry Titov, 2016/09/09 04:33:06]

Need to update comment here - there is no more kLoadingOfflinePageHeader. Same
in below comments.

[jianli, 2016/09/10 00:56:04]

Done.

+// offline info in this header should be persisted across session restore.
+extern const char kOfflinePageHeaderPersistKey[];

[Dmitry Titov, 2016/09/09 04:33:06]

Is this from a separate CL? This CL does not seem to deal with persistence.

[jianli, 2016/09/10 00:56:04]

Another CL (https://codereview.chromium.org/2310363002/) adds the "persist"
field, but the parsing of it is done strictly in place to allow easy merge into
M54 if needed.

I just want this OfflinePageHeader parsing class to also handle this additional
field. After landing these 2 patches, I am going to have a 3rd patch to move
OfflinePageHeader into components/offline_pages/request_header in order for
ContentSerializedNavigationBuilder to call the common header parsing code.

 // The name used in name-value pair of kLoadingOfflinePageHeader to denote the
 // reason for loading offline page.
-extern const char kLoadingOfflinePageReason[];
+extern const char kOfflinePageHeaderReasonKey[];
 // Possible values in name-value pair that denote the reason for loading offline
 // page.
-extern const char kLoadingOfflinePageDueToNetError[];
+extern const char kOfflinePageHeaderReasonValueDueToNetError[];
+// The name used in name-value pair of kLoadingOfflinePageHeader to denote the
+// namespace of the offline page to load.
+extern const char kOfflinePageHeaderNamespaceKey[];
+// The name used in name-value pair of kLoadingOfflinePageHeader to denote the
+// ID of the offline page to load. If kOfflinePageNamespace value exists, this
+// ID is the client ID within the specific namespace. Otherwise, this ID is the
+// offline ID.
+extern const char kOfflinePageHeaderIDKey[];
 
 // A request job that serves content from offline file.
 class OfflinePageRequestJob : public net::URLRequestFileJob {
  public:
   // This enum is used for UMA reporting. It contains all possible outcomes of
   // handling requests that might service offline page in different network
   // conditions. Generally one of these outcomes will happen.
   // The fringe errors (like no OfflinePageModel, etc.) are not reported due
   // to their low probability.
   // NOTE: because this is used for UMA reporting, these values should not be
@@ skipping 66 matching lines @@
   std::unique_ptr<Delegate> delegate_;
 
   base::WeakPtrFactory<OfflinePageRequestJob> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageRequestJob);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_OFFLINE_PAGE_REQUEST_JOB_H_