Don't load plugins on prerendered pages until the pages are displayed....

chrome/renderer/navigation_state.h

 // Copyright (c) 2009 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.
 
 #ifndef CHROME_RENDERER_NAVIGATION_STATE_H_
 #define CHROME_RENDERER_NAVIGATION_STATE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 14 matching lines @@
 
 // The RenderView stores an instance of this class in the "extra data" of each
 // WebDataSource (see RenderView::DidCreateDataSource).
 class NavigationState : public WebKit::WebDataSource::ExtraData {
  public:
   enum LoadType {
     UNDEFINED_LOAD,            // Not yet initialized.
     RELOAD,                    // User pressed reload.
     HISTORY_LOAD,              // Back or forward.
     NORMAL_LOAD,               // User entered URL, or omnibox search.
+    PRERENDER_LOAD,            // Navigation started as the speculatively
+                               // prendering of a linked page.
     LINK_LOAD,                 // (deprecated) Included next 4 categories.
     LINK_LOAD_NORMAL,          // Commonly following of link.
     LINK_LOAD_RELOAD,          // JS/link directed reload.
     LINK_LOAD_CACHE_STALE_OK,  // back/forward or encoding change.
     LINK_LOAD_CACHE_ONLY,      // Allow stale data (avoid doing a re-post)
     kLoadTypeMax               // Bounding value for this enum.
   };
 
   virtual ~NavigationState();
 
@@ skipping 158 matching lines @@
   void set_postpone_loading_data(bool postpone_loading_data) {
     postpone_loading_data_ = postpone_loading_data;
   }
 
   const std::string& postponed_data() const { return postponed_data_; }
   void clear_postponed_data() { postponed_data_.clear(); }
   void append_postponed_data(const char* data, size_t data_len) {
     postponed_data_.append(data, data_len);
   }
 
+  bool is_prerendering() const { return is_prerendering_; }
+  void set_is_prerendering(bool is_prerendering) {
+    is_prerendering_ = is_prerendering;
+  }
+
   int http_status_code() const { return http_status_code_; }
   void set_http_status_code(int http_status_code) {
     http_status_code_ = http_status_code;
   }
 
   // Sets the cache policy. The cache policy is only used if explicitly set and
   // by default is not set. You can mark a NavigationState as not having a cache
   // state by way of clear_cache_policy_override.
   void set_cache_policy_override(
       WebKit::WebURLRequest::CachePolicy cache_policy) {
@@ skipping 71 matching lines @@
   int32 pending_page_id_;
   int pending_history_list_offset_;
   GURL searchable_form_url_;
   std::string searchable_form_encoding_;
   scoped_ptr<webkit_glue::PasswordForm> password_form_data_;
   scoped_ptr<webkit_glue::AltErrorPageResourceFetcher> alt_error_page_fetcher_;
   std::string security_info_;
   bool postpone_loading_data_;
   std::string postponed_data_;
 
+  // True if page is being prerendered.  False once prerendered page is
+  // displayed.
+  bool is_prerendering_;
+
   bool cache_policy_override_set_;
   WebKit::WebURLRequest::CachePolicy cache_policy_override_;
 
   scoped_ptr<UserScriptIdleScheduler> user_script_idle_scheduler_;
   int http_status_code_;
 
   bool was_fetched_via_spdy_;
   bool was_npn_negotiated_;
   bool was_alternate_protocol_available_;
   bool was_fetched_via_proxy_;
   bool was_translated_;
   bool was_within_same_page_;
 
   // A prefetcher is a page that contains link rel=prefetch elements.
   bool was_prefetcher_;
   bool was_referred_by_prefetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationState);
 };
 
 #endif  // CHROME_RENDERER_NAVIGATION_STATE_H_