Adding a command-line flag to set MHTML generation options.

content/browser/download/save_package.cc

 // Copyright (c) 2012 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 "content/browser/download/save_package.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/i18n/file_util_icu.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/stl_util.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 20 matching lines @@
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/download_manager_delegate.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/common/mhtml_generation_params.h"
 #include "net/base/filename_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/mime_util.h"
 #include "net/url_request/url_request_context.h"
 #include "url/url_constants.h"
 
 namespace content {
 namespace {
 
@@ skipping 272 matching lines @@
   if (!download_created_callback.is_null())
     download_created_callback.Run(download_);
 
   // Check save type and process the save page job.
   if (save_type_ == SAVE_PAGE_TYPE_AS_COMPLETE_HTML) {
     // Get directory
     DCHECK(!saved_main_directory_path_.empty());
     GetSavableResourceLinks();
   } else if (save_type_ == SAVE_PAGE_TYPE_AS_MHTML) {
     MHTMLGenerationParams mhtml_generation_params(saved_main_file_path_);
+
+    // Check which variant of MHTML generation is required.
+    std::string MHTMLGeneratorOptionFlag =

[dewittj, 2016/05/24 23:03:20]

Another option would be to override the default in MHTMLGenerationManager, which
would then apply to extension API as well...

+        base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+        switches::kMHTMLGeneratorOption);
+
+    if (MHTMLGeneratorOptionFlag == "skip_nostore_main") {

[dewittj, 2016/05/24 23:03:20]

hm, wish this could be a constant that's shared in the about_flags.cc as well.

+      mhtml_generation_params.cache_control_policy =
+          blink::WebFrameSerializerCacheControlPolicy::
+          FailForNoStoreMainFrame;
+    } else if (MHTMLGeneratorOptionFlag == "skip_nostore_all") {
+      mhtml_generation_params.cache_control_policy =
+          blink::WebFrameSerializerCacheControlPolicy::
+          SkipAnyFrameOrResourceMarkedNoStore;
+    }
+
     web_contents()->GenerateMHTML(
         mhtml_generation_params,
         base::Bind(&SavePackage::OnMHTMLGenerated, this));
   } else {
     DCHECK_EQ(SAVE_PAGE_TYPE_AS_ONLY_HTML, save_type_);
     wait_state_ = NET_FILES;
     SaveFileCreateInfo::SaveFileSource save_source = page_url_.SchemeIsFile() ?
         SaveFileCreateInfo::SAVE_FILE_FROM_FILE :
         SaveFileCreateInfo::SAVE_FILE_FROM_NET;
     // Add this item to waiting list.
@@ skipping 1143 matching lines @@
 }
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
 
   download_manager_->OnSavePackageSuccessfullyFinished(download_);
   StopObservation();
 }
 
 }  // namespace content