Remove PluginLoadObserver and related logic, it was only used for NPAPI.

content/plugin/webplugin_delegate_stub.h

Index: content/plugin/webplugin_delegate_stub.h
diff --git a/content/plugin/webplugin_delegate_stub.h b/content/plugin/webplugin_delegate_stub.h
index 63964e11555c31eaf604b499528c0b2c6af52e9a..13a8d480e9d96f55394ec7f014ccb88d42a4d27c 100644
--- a/content/plugin/webplugin_delegate_stub.h
+++ b/content/plugin/webplugin_delegate_stub.h
@@ -67,7 +67,6 @@ class WebPluginDelegateStub : public IPC::Listener,
                         int data_offset);
   void OnDidFinishLoading(int id);
   void OnDidFail(int id);
-  void OnDidFinishLoadWithReason(const GURL& url, int reason, int notify_id);
   void OnSetFocus(bool focused);
   void OnHandleInputEvent(const blink::WebInputEvent* event,
                           bool* handled, WebCursor* cursor);
@@ -77,8 +76,7 @@ class WebPluginDelegateStub : public IPC::Listener,
   void OnGetPluginScriptableObject(int* route_id);
   void OnSendJavaScriptStream(const GURL& url,
                               const std::string& result,
-                              bool success,
-                              int notify_id);
+                              bool success);
   void OnGetFormValue(base::string16* value, bool* success);
 
   void OnSetContentAreaFocus(bool has_focus);
@@ -106,8 +104,7 @@ class WebPluginDelegateStub : public IPC::Listener,
   void OnDidFinishManualLoading();
   void OnDidManualLoadFail();
   void OnHandleURLRequestReply(unsigned long resource_id,
-                               const GURL& url,
-                               int notify_id);
+                               const GURL& url);
   void OnHTTPRangeRequestReply(unsigned long resource_id, int range_request_id);
   void OnFetchURL(const PluginMsg_FetchURL_Params& params);