PlzNavigate: add PDF viewer bypass hack to avoid crash.

content/browser/loader/mime_type_resource_handler.cc

Index: content/browser/loader/mime_type_resource_handler.cc
diff --git a/content/browser/loader/mime_type_resource_handler.cc b/content/browser/loader/mime_type_resource_handler.cc
index 59c2b5310660487b1a0ccdc7f9591da7ebcc14bc..be40d9f96de5d35a3c563bba4ca6dc76cee8037e 100644
--- a/content/browser/loader/mime_type_resource_handler.cc
+++ b/content/browser/loader/mime_type_resource_handler.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ -27,6 +28,7 @@
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/common/resource_response.h"
 #include "content/public/common/webplugininfo.h"
 #include "net/base/io_buffer.h"
@@ -417,7 +419,11 @@ bool MimeTypeResourceHandler::UseAlternateNextHandler(
   // which does so is CrossSiteResourceHandler. Cross-site transitions should
   // not trigger when switching handlers.
   DCHECK(!defer_ignored);
-  if (payload_for_old_handler.empty()) {
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+  if (payload_for_old_handler.empty() ||
+      (base::CommandLine::ForCurrentProcess()->HasSwitch(
+           switches::kEnableBrowserSideNavigation) &&
+       (info->IsDownload() || info->is_stream()))) {

[davidben, 2015/09/01 18:22:56]

I was actually thinking we should do:

if (!plz_navigate || !is_a_navigation) {
  // Current logic. Send either OnResponseStarted + OnResponseCompleted or
OnResponseStarted + OnWillRead + OnReadCompleted + OnResponseStarted depending
on payload_for_old_handler
} else {
  // Only send OnResponseCompleted with ERR_ABORTED and nothing else at all.
}

And then the entire info->IsDownload() || info->is_stream() check in
NavigationResourceHandler can go away completely. That's only needed because we
send OnResponseStarted for intercepted navigations, in turn only needed because
we send the request to DevTools that way by way of the renderer. But since we're
going to need to come up with another way to get the request to DevTools, may as
well not bother at all.

(Not sure if is_a_navigation should check for MAIN_FRAME or MAIN_FRAME +
SUB_FRAME. How does PlzNavigate on + OOPIF off behave? Does that exist?)

     net::URLRequestStatus status(net::URLRequestStatus::CANCELED,
                                  net::ERR_ABORTED);
     next_handler_->OnResponseCompleted(status, std::string(), &defer_ignored);