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

content/renderer/npapi/webplugin_delegate_proxy.cc

Index: content/renderer/npapi/webplugin_delegate_proxy.cc
diff --git a/content/renderer/npapi/webplugin_delegate_proxy.cc b/content/renderer/npapi/webplugin_delegate_proxy.cc
index edd39bdad7c29ccad1c3605b16415d9a5693f106..e9b69af2c018d856d8108abd968fd4b59f2b8763 100644
--- a/content/renderer/npapi/webplugin_delegate_proxy.cc
+++ b/content/renderer/npapi/webplugin_delegate_proxy.cc
@@ -102,10 +102,10 @@ class ResourceClientProxy : public WebPluginResourceClient {
 
   ~ResourceClientProxy() override {}
 
-  void Initialize(unsigned long resource_id, const GURL& url, int notify_id) {
+  void Initialize(unsigned long resource_id, const GURL& url) {
     resource_id_ = resource_id;
     channel_->Send(new PluginMsg_HandleURLRequestReply(
-        instance_id_, resource_id, url, notify_id));
+        instance_id_, resource_id, url));
   }
 
   void InitializeForSeekableStream(unsigned long resource_id,
@@ -388,10 +388,8 @@ bool WebPluginDelegateProxy::Send(IPC::Message* msg) {
 
 void WebPluginDelegateProxy::SendJavaScriptStream(const GURL& url,
                                                   const std::string& result,
-                                                  bool success,
-                                                  int notify_id) {
-  Send(new PluginMsg_SendJavaScriptStream(
-      instance_id_, url, result, success, notify_id));
+                                                  bool success) {
+  Send(new PluginMsg_SendJavaScriptStream(instance_id_, url, result, success));
 }
 
 void WebPluginDelegateProxy::DidReceiveManualResponse(
@@ -741,12 +739,6 @@ bool WebPluginDelegateProxy::GetFormValue(base::string16* value) {
   return success;
 }
 
-void WebPluginDelegateProxy::DidFinishLoadWithReason(
-    const GURL& url, NPReason reason, int notify_id) {
-  Send(new PluginMsg_DidFinishLoadWithReason(
-      instance_id_, url, reason, notify_id));
-}
-
 void WebPluginDelegateProxy::SetFocus(bool focused) {
   Send(new PluginMsg_SetFocus(instance_id_, focused));
 #if defined(OS_WIN)
@@ -1077,18 +1069,18 @@ void WebPluginDelegateProxy::OnHandleURLRequest(
 
   plugin_->HandleURLRequest(
       params.url.c_str(), params.method.c_str(), target, data,
-      static_cast<unsigned int>(params.buffer.size()), params.notify_id,
+      static_cast<unsigned int>(params.buffer.size()),
       params.popups_allowed, params.notify_redirects);
 }
 
 WebPluginResourceClient* WebPluginDelegateProxy::CreateResourceClient(
-    unsigned long resource_id, const GURL& url, int notify_id) {
+    unsigned long resource_id, const GURL& url) {
   if (!channel_host_.get())
     return NULL;
 
   ResourceClientProxy* proxy =
       new ResourceClientProxy(channel_host_.get(), instance_id_);
-  proxy->Initialize(resource_id, url, notify_id);
+  proxy->Initialize(resource_id, url);
   return proxy;
 }
 
@@ -1104,7 +1096,6 @@ WebPluginResourceClient* WebPluginDelegateProxy::CreateSeekableResourceClient(
 }
 
 void WebPluginDelegateProxy::FetchURL(unsigned long resource_id,
-                                      int notify_id,
                                       const GURL& url,
                                       const GURL& first_party_for_cookies,
                                       const std::string& method,
@@ -1118,7 +1109,6 @@ void WebPluginDelegateProxy::FetchURL(unsigned long resource_id,
                                       int render_view_id) {
   PluginMsg_FetchURL_Params params;
   params.resource_id = resource_id;
-  params.notify_id = notify_id;
   params.url = url;
   params.first_party_for_cookies = first_party_for_cookies;
   params.method = method;