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

chrome/renderer/navigation_state.h

Index: chrome/renderer/navigation_state.h
===================================================================
--- chrome/renderer/navigation_state.h	(revision 71683)
+++ chrome/renderer/navigation_state.h	(working copy)
@@ -32,6 +32,8 @@
     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.
@@ -210,6 +212,11 @@
     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;
@@ -301,6 +308,10 @@
   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_;