Ensure we don't load plugins on the IO thread

chrome/browser/renderer_host/buffered_resource_handler.cc

Index: chrome/browser/renderer_host/buffered_resource_handler.cc
===================================================================
--- chrome/browser/renderer_host/buffered_resource_handler.cc	(revision 23449)
+++ chrome/browser/renderer_host/buffered_resource_handler.cc	(working copy)
@@ -9,12 +9,15 @@
 #include "base/string_util.h"
 #include "net/base/mime_sniffer.h"
 #include "net/base/net_errors.h"
+#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/renderer_host/download_throttling_resource_handler.h"
 #include "chrome/browser/renderer_host/resource_dispatcher_host.h"
 #include "chrome/common/url_constants.h"
 #include "net/base/mime_sniffer.h"
+#include "net/base/mime_util.h"
 #include "net/base/io_buffer.h"
 #include "net/http/http_response_headers.h"
+#include "webkit/glue/plugins/plugin_list.h"
 
 namespace {
 
@@ -49,6 +52,7 @@
       bytes_read_(0),
       sniff_content_(false),
       should_buffer_(false),
+      wait_for_plugins_(false),
       buffering_(false),
       finished_(false) {
 }
@@ -75,7 +79,6 @@
   return true;
 }
 
-
 bool BufferedResourceHandler::OnResponseCompleted(
     int request_id,
     const URLRequestStatus& status,
@@ -83,6 +86,11 @@
   return real_handler_->OnResponseCompleted(request_id, status, security_info);
 }
 
+void BufferedResourceHandler::OnRequestClosed() {
+  request_ = NULL;
+  real_handler_->OnRequestClosed();
+}
+
 // We'll let the original event handler provide a buffer, and reuse it for
 // subsequent reads until we're done buffering.
 bool BufferedResourceHandler::OnWillRead(int request_id, net::IOBuffer** buf,
@@ -118,12 +126,13 @@
       return true;
 
     LOG(INFO) << "Finished buffering " << request_->url().spec();
-    sniff_content_ = should_buffer_ = false;
     *bytes_read = bytes_read_;
 
     // Done buffering, send the pending ResponseStarted event.
     if (!CompleteResponseStarted(request_id, true))
       return false;
+  } else if (wait_for_plugins_) {
+    return true;
   }
 
   // Release the reference that we acquired at OnWillRead.
@@ -171,6 +180,12 @@
     LOG(INFO) << "To buffer: " << request_->url().spec();
     return true;
   }
+
+  if (ShouldWaitForPlugins()) {
+    wait_for_plugins_ = true;
+    return true;
+  }
+
   return false;
 }
 
@@ -189,6 +204,12 @@
   return mime_type == "text/html";
 }
 
+bool BufferedResourceHandler::DidBufferEnough(int bytes_read) {
+  const int kRequiredLength = 256;
+
+  return bytes_read >= kRequiredLength;
+}
+
 bool BufferedResourceHandler::KeepBuffering(int bytes_read) {
   DCHECK(read_buffer_);
   if (my_buffer_) {
@@ -219,17 +240,29 @@
     response_->response_head.mime_type.assign(new_type);
 
     // We just sniffed the mime type, maybe there is a doctype to process.
-    if (ShouldBuffer(request_->url(), new_type))
+    if (ShouldBuffer(request_->url(), new_type)) {
       should_buffer_ = true;
+    } else if (ShouldWaitForPlugins()) {
+      wait_for_plugins_ = true;
+    }
   }
 
-  if (!finished_ && should_buffer_) {
-    if (!DidBufferEnough(bytes_read_)) {
+  if (should_buffer_) {
+    if (!finished_ && !DidBufferEnough(bytes_read_)) {
       buffering_ = true;
       return true;
     }
+
+    should_buffer_ = false;
+    if (ShouldWaitForPlugins())
+      wait_for_plugins_ = true;
   }
+
   buffering_ = false;
+
+  if (wait_for_plugins_)
+    return true;
+
   return false;
 }
 
@@ -238,16 +271,10 @@
   // Check to see if we should forward the data from this request to the
   // download thread.
   // TODO(paulg): Only download if the context from the renderer allows it.
-  std::string content_disposition;
-  request_->GetResponseHeaderByName("content-disposition",
-                                    &content_disposition);
-
   ResourceDispatcherHost::ExtraRequestInfo* info =
       ResourceDispatcherHost::ExtraInfoForRequest(request_);
 
-  if (info->allow_download &&
-      host_->ShouldDownload(response_->response_head.mime_type,
-                            content_disposition)) {
+  if (info->allow_download && ShouldDownload(NULL)) {
     if (response_->response_head.headers &&  // Can be NULL if FTP.
         response_->response_head.headers->response_code() / 100 != 2) {
       // The response code indicates that this is an error page, but we don't
@@ -293,8 +320,97 @@
   return real_handler_->OnResponseStarted(request_id, response_);
 }
 
-bool BufferedResourceHandler::DidBufferEnough(int bytes_read) {
-  const int kRequiredLength = 256;
+bool BufferedResourceHandler::ShouldWaitForPlugins() {
+  bool need_plugin_list;
+  if (!ShouldDownload(&need_plugin_list) || !need_plugin_list)
+    return false;
 
-  return bytes_read >= kRequiredLength;
+  // We don't want to keep buffering as our buffer will fill up.
+  ResourceDispatcherHost::ExtraRequestInfo* info =
+      ResourceDispatcherHost::ExtraInfoForRequest(request_);
+  host_->PauseRequest(info->process_id, info->request_id, true);
+
+  // Schedule plugin loading on the file thread.
+  ChromeThread::GetMessageLoop(ChromeThread::FILE)->PostTask(FROM_HERE,
+      NewRunnableMethod(this, &BufferedResourceHandler::LoadPlugins));
+  return true;
 }
+
+// This test mirrors the decision that WebKit makes in
+// WebFrameLoaderClient::dispatchDecidePolicyForMIMEType.
+bool BufferedResourceHandler::ShouldDownload(bool* need_plugin_list) {
+  if (need_plugin_list)
+    *need_plugin_list = false;
+  std::string type = StringToLowerASCII(response_->response_head.mime_type);
+  std::string disposition;
+  request_->GetResponseHeaderByName("content-disposition", &disposition);
+  disposition = StringToLowerASCII(disposition);
+
+  // First, examine content-disposition.
+  if (!disposition.empty()) {
+    bool should_download = true;
+
+    // Some broken sites just send ...
+    //    Content-Disposition: ; filename="file"
+    // ... screen those out here.
+    if (disposition[0] == ';')
+      should_download = false;
+
+    if (disposition.compare(0, 6, "inline") == 0)
+      should_download = false;
+
+    // Some broken sites just send ...
+    //    Content-Disposition: filename="file"
+    // ... without a disposition token... Screen those out.
+    if (disposition.compare(0, 8, "filename") == 0)
+      should_download = false;
+
+    // Also in use is Content-Disposition: name="file"
+    if (disposition.compare(0, 4, "name") == 0)
+      should_download = false;
+
+    // We have a content-disposition of "attachment" or unknown.
+    // RFC 2183, section 2.8 says that an unknown disposition
+    // value should be treated as "attachment".
+    if (should_download)
+      return true;
+  }
+
+  // MIME type checking.
+  if (net::IsSupportedMimeType(type))
+    return false;
+
+  if (need_plugin_list) {
+    if (!NPAPI::PluginList::Singleton()->PluginsLoaded()) {
+      *need_plugin_list = true;
+      return true;
+    }
+  } else {
+    DCHECK(NPAPI::PluginList::Singleton()->PluginsLoaded());
+  }
+
+  // Finally, check the plugin list.
+  WebPluginInfo info;
+  bool allow_wildcard = false;
+  return !NPAPI::PluginList::Singleton()->GetPluginInfo(
+      GURL(), type, "", allow_wildcard, &info, NULL);
+}
+
+void BufferedResourceHandler::LoadPlugins() {
+  std::vector<WebPluginInfo> plugins;
+  NPAPI::PluginList::Singleton()->GetPlugins(false, &plugins);
+  ChromeThread::GetMessageLoop(ChromeThread::IO)->PostTask(FROM_HERE,
+      NewRunnableMethod(this, &BufferedResourceHandler::OnPluginsLoaded));
+}
+
+void BufferedResourceHandler::OnPluginsLoaded() {
+  wait_for_plugins_ = false;
+  if (!request_)
+    return;
+
+  ResourceDispatcherHost::ExtraRequestInfo* info =
+      ResourceDispatcherHost::ExtraInfoForRequest(request_);
+  host_->PauseRequest(info->process_id, info->request_id, false);
+  if (!CompleteResponseStarted(info->request_id, false))
+    host_->CancelRequest(info->process_id, info->request_id, false);
+}