[Offline Pages] Make new archives have random file names.

chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc

Index: chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc b/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
index 0600f24a74e876b5134ace330460983e24cd0e5e..1e54d51c8b830678f74dce926607974191fc1d35 100644
--- a/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
+++ b/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
@@ -8,6 +8,7 @@
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
+#include "base/guid.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
@@ -25,13 +26,6 @@
 namespace offline_pages {
 namespace {
 const base::FilePath::CharType kMHTMLExtension[] = FILE_PATH_LITERAL("mhtml");
-const base::FilePath::CharType kDefaultFileName[] =
-    FILE_PATH_LITERAL("offline_page");
-const int kTitleLengthMax = 80;
-const char kMHTMLFileNameExtension[] = ".mhtml";
-const char kFileNameComponentsSeparator[] = "-";
-const char kReplaceChars[] = " ";
-const char kReplaceWith[] = "_";
 
 void DeleteFileOnFileThread(const base::FilePath& file_path,
                             const base::Closure& callback) {
@@ -44,34 +38,6 @@ void DeleteFileOnFileThread(const base::FilePath& file_path,
 }  // namespace
 
 // static
-std::string OfflinePageMHTMLArchiver::GetFileNameExtension() {
-    return kMHTMLFileNameExtension;
-}
-
-// static
-base::FilePath OfflinePageMHTMLArchiver::GenerateFileName(
-    const GURL& url,
-    const std::string& title,
-    int64_t archive_id) {
-  std::string title_part(title.substr(0, kTitleLengthMax));
-  std::string suggested_name(
-      url.host() + kFileNameComponentsSeparator +
-      title_part + kFileNameComponentsSeparator +
-      base::Int64ToString(archive_id));
-
-  // Substitute spaces out from title.
-  base::ReplaceChars(suggested_name, kReplaceChars, kReplaceWith,
-                     &suggested_name);
-
-  return net::GenerateFileName(url,
-                               std::string(),  // content disposition
-                               std::string(),  // charset
-                               suggested_name,
-                               std::string(),  // mime-type
-                               kDefaultFileName)
-      .AddExtension(kMHTMLExtension);
-}
-
 OfflinePageMHTMLArchiver::OfflinePageMHTMLArchiver(
     content::WebContents* web_contents)
     : web_contents_(web_contents),
@@ -129,9 +95,7 @@ void OfflinePageMHTMLArchiver::GenerateMHTML(
   GURL url(web_contents_->GetLastCommittedURL());
   base::string16 title(web_contents_->GetTitle());
   base::FilePath file_path(
-      archives_dir.Append(
-          GenerateFileName(url, base::UTF16ToUTF8(title), archive_id)));
-
+      archives_dir.Append(base::GenerateGUID()).AddExtension(kMHTMLExtension));

[Pete Williamson, 2017/01/03 20:32:30]

Drive by: This means that if we generate another page for the same file, it
won't collide or overwrite.  Are we sure there is nothing depending on a
collision in case of a duplicate?

[dewittj, 2017/01/03 22:23:38]

We do currently exhibit this behavior when we manage to save 2 copies of a page
with RecentTabHelper.  This is the cause of the ALREADY_EXISTS error.  However,
it is better to clarify the behavior (already exists error does not update
archive) and then to change policy if necessary rather than leave it in this
strange state.

   content::MHTMLGenerationParams params(file_path);
   params.use_binary_encoding = true;