Plugin Power Saver: Make PPS work well with prerendered pages.

chrome/renderer/plugins/chrome_plugin_placeholder.cc

Index: chrome/renderer/plugins/chrome_plugin_placeholder.cc
diff --git a/chrome/renderer/plugins/chrome_plugin_placeholder.cc b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
index c532fdd2c2c7c3e23014a9160373e77cf3429683..402bfb6f3e87fa1701962e94f540962cd2ba6d6e 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.cc
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
@@ -13,6 +13,7 @@
 #include "chrome/grit/renderer_resources.h"
 #include "chrome/renderer/chrome_content_renderer_client.h"
 #include "chrome/renderer/custom_menu_commands.h"
+#include "chrome/renderer/plugins/plugin_preroller.h"
 #include "chrome/renderer/plugins/plugin_uma.h"
 #include "components/content_settings/content/common/content_settings_messages.h"
 #include "content/app/strings/grit/content_strings.h"
@@ -366,6 +367,24 @@ void ChromePluginPlaceholder::ShowContextMenu(const WebMouseEvent& event) {
 #endif  // OS_ANDROID
 }
 
+blink::WebPlugin* ChromePluginPlaceholder::CreatePlugin() {
+  scoped_ptr<content::PluginInstanceThrottler> throttler;
+#if defined(ENABLE_PLUGINS)
+  // If the plugin has already been marked essential in its placeholder form,
+  // we shouldn't create a new throttler and start the process all over again.
+  if (power_saver_enabled()) {
+    throttler = content::PluginInstanceThrottler::Create();
+    // PluginPreroller manages its own lifetime.
+    new PluginPreroller(render_frame(), GetFrame(), GetPluginParams(),
+                        GetPluginInfo(), GetIdentifier(), title_,
+                        l10n_util::GetStringFUTF16(IDS_PLUGIN_BLOCKED, title_),
+                        throttler.get());
+  }
+#endif
+  return render_frame()->CreatePlugin(GetFrame(), GetPluginInfo(),
+                                      GetPluginParams(), throttler.Pass());
+}
+
 gin::ObjectTemplateBuilder ChromePluginPlaceholder::GetObjectTemplateBuilder(
     v8::Isolate* isolate) {
   return LoadablePluginPlaceholder::GetObjectTemplateBuilder(isolate).SetMethod(