Preserving Content-Type header from http request in OpenURL path.

chrome/browser/prerender/prerender_manager.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 "chrome/browser/prerender/prerender_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <functional>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
+#include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/values.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
@@ skipping 19 matching lines @@
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_request_details.h"
 #include "content/public/browser/session_storage_namespace.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/constants.h"
+#include "net/http/http_request_headers.h"
 #include "ui/gfx/geometry/rect.h"
 
 using content::BrowserThread;
 using content::RenderViewHost;
 using content::SessionStorageNamespace;
 using content::WebContents;
 using namespace chrome_browser_net;
 
 namespace prerender {
 
 namespace {
 
 // Time interval at which periodic cleanups are performed.
 const int kPeriodicCleanupIntervalMs = 1000;
 
 // Length of prerender history, for display in chrome://net-internals
 const int kHistoryLength = 100;
 
+// Check if |extra_headers| requested via chrome::NavigateParams::extra_headers
+// are the same as what the HTTP server saw when serving prerendered contents.
+// PrerenderContents::StartPrerendering doesn't specify any extra headers when
+// calling content::NavigationController::LoadURLWithParams, but in reality
+// Blink will always add an Upgrade-Insecure-Requests http request header, so
+// that HTTP request for prerendered contents always includes this header.
+// Because of this, it is okay to show prerendered contents even if
+// |extra_headers| contains "Upgrade-Insecure-Requests" header.

[mmenke, 2016/10/06 20:52:02]

Would it make more sense to just add "Upgrade-Insecure-Requests" in
ResourceDispatcherHost instead?  A bit less IPC overhead, less redundant memory
use, etc.  Not expecting big savings, just wondiner if there's a reason for the
current architecture (And not a big fan of having magic here)

[Łukasz Anforowicz, 2016/10/06 21:23:34]

Okay - let me try to see how this works out.  I gave a heads-up to mkwst@ +
shared some notes at https://crbug.com/648648#c13

+bool AreExtraHeadersCompatibleWithPrerenderedContents(
+    const std::string& extra_headers) {
+  net::HttpRequestHeaders parsed_headers;
+  parsed_headers.AddHeadersFromString(extra_headers);
+
+  net::HttpRequestHeaders::Iterator it(parsed_headers);
+  while (it.GetNext()) {
+    if (!base::EqualsCaseInsensitiveASCII(it.name(),
+                                          "upgrade-insecure-requests"))
+      return false;
+  }
+
+  return true;
+}

[mmenke, 2016/10/06 20:52:02]

Also, should we have a prerender browser test for this?  I don't think the
layout test you added tests this code?

[Łukasz Anforowicz, 2016/10/06 21:23:34]

The existing prerender browser tests already exercise this code - they would
have failed without ignoring this header - see
https://crrev.com/2355023002/#ps20001 and the discussion started in
https://crbug.com/648648#c3

+
 }  // namespace
 
 class PrerenderManager::OnCloseWebContentsDeleter
     : public content::WebContentsDelegate,
       public base::SupportsWeakPtr<
           PrerenderManager::OnCloseWebContentsDeleter> {
  public:
   OnCloseWebContentsDeleter(PrerenderManager* manager,
                             std::unique_ptr<WebContents> tab)
       : manager_(manager), tab_(std::move(tab)), suppressed_dialog_(false) {
@@ skipping 200 matching lines @@
   }
 }
 
 bool PrerenderManager::MaybeUsePrerenderedPage(const GURL& url,
                                                chrome::NavigateParams* params) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   WebContents* web_contents = params->target_contents;
   DCHECK(!IsWebContentsPrerendering(web_contents, nullptr));
 
-  // Don't prerender if the navigation involves some special parameters.
-  if (params->uses_post || !params->extra_headers.empty())
+  // Don't prerender if the navigation involves some special parameters that
+  // are different from what was used by PrerenderContents::StartPrerendering
+  // (which always uses GET method and doesn't specify any extra headers when
+  // calling content::NavigationController::LoadURLWithParams).
+  if (params->uses_post ||
+      !AreExtraHeadersCompatibleWithPrerenderedContents(params->extra_headers))
     return false;

[mmenke, 2016/10/06 20:52:02]

nit:  Add braces when if condition takes up more than 1 line.

[Łukasz Anforowicz, 2016/10/06 21:23:34]

Done.

 
   DeleteOldEntries();
   to_delete_prerenders_.clear();
 
   // First, try to find prerender data with the correct session storage
   // namespace.
   // TODO(ajwong): This doesn't handle isolated apps correctly.
   PrerenderData* prerender_data = FindPrerenderData(
       url,
       web_contents->GetController().GetDefaultSessionStorageNamespace());
@@ skipping 1029 matching lines @@
   DCHECK_EQ(1u, erased);
 }
 
 void PrerenderManager::SetPrerenderContentsFactoryForTest(
     PrerenderContents::Factory* prerender_contents_factory) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   prerender_contents_factory_.reset(prerender_contents_factory);
 }
 
 }  // namespace prerender