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

content/child/plugin_messages.h

 // Copyright 2013 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.
 //
 // Multiply-included message file, hence no include guard.
 
 #include "build/build_config.h"
 #include "content/child/plugin_param_traits.h"
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
@@ skipping 21 matching lines @@
   IPC_STRUCT_MEMBER(std::vector<std::string>, arg_values)
   IPC_STRUCT_MEMBER(bool, load_manually)
   IPC_STRUCT_MEMBER(int, host_render_view_routing_id)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(PluginHostMsg_URLRequest_Params)
   IPC_STRUCT_MEMBER(std::string, url)
   IPC_STRUCT_MEMBER(std::string, method)
   IPC_STRUCT_MEMBER(std::string, target)
   IPC_STRUCT_MEMBER(std::vector<char>, buffer)
-  IPC_STRUCT_MEMBER(int, notify_id)
   IPC_STRUCT_MEMBER(bool, popups_allowed)
   IPC_STRUCT_MEMBER(bool, notify_redirects)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(PluginMsg_DidReceiveResponseParams)
   IPC_STRUCT_MEMBER(unsigned long, id)
   IPC_STRUCT_MEMBER(std::string, mime_type)
   IPC_STRUCT_MEMBER(std::string, headers)
   IPC_STRUCT_MEMBER(uint32, expected_length)
   IPC_STRUCT_MEMBER(uint32, last_modified)
   IPC_STRUCT_MEMBER(bool, request_is_seekable)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(PluginMsg_FetchURL_Params)
   IPC_STRUCT_MEMBER(unsigned long, resource_id)
-  IPC_STRUCT_MEMBER(int, notify_id)
   IPC_STRUCT_MEMBER(GURL, url)
   IPC_STRUCT_MEMBER(GURL, first_party_for_cookies)
   IPC_STRUCT_MEMBER(std::string, method)
   IPC_STRUCT_MEMBER(std::vector<char>, post_data)
   IPC_STRUCT_MEMBER(GURL, referrer)
   IPC_STRUCT_MEMBER(blink::WebReferrerPolicy, referrer_policy)
   IPC_STRUCT_MEMBER(bool, notify_redirect)
   IPC_STRUCT_MEMBER(bool, is_plugin_src_load)
   IPC_STRUCT_MEMBER(int, render_frame_id)
 IPC_STRUCT_END()
@@ skipping 40 matching lines @@
 IPC_MESSAGE_ROUTED0(PluginMsg_DidPaint)
 
 IPC_SYNC_MESSAGE_ROUTED0_1(PluginMsg_GetPluginScriptableObject,
                            int /* route_id */)
 
 // Gets the form value of the plugin instance synchronously.
 IPC_SYNC_MESSAGE_ROUTED0_2(PluginMsg_GetFormValue,
                            base::string16 /* value */,
                            bool /* success */)
 
-IPC_MESSAGE_ROUTED3(PluginMsg_DidFinishLoadWithReason,
-                    GURL /* url */,
-                    int /* reason */,
-                    int /* notify_id */)
-
 // Updates the plugin location.
 IPC_MESSAGE_ROUTED1(PluginMsg_UpdateGeometry,
                     PluginMsg_UpdateGeometry_Param)
 
 // A synchronous version of above.
 IPC_SYNC_MESSAGE_ROUTED1_0(PluginMsg_UpdateGeometrySync,
                            PluginMsg_UpdateGeometry_Param)
 
 IPC_SYNC_MESSAGE_ROUTED1_0(PluginMsg_SetFocus,
                            bool /* focused */)
@@ skipping 18 matching lines @@
                     unsigned long /* id */,
                     std::vector<char> /* buffer */,
                     int /* data_offset */)
 
 IPC_MESSAGE_ROUTED1(PluginMsg_DidFinishLoading,
                     unsigned long /* id */)
 
 IPC_MESSAGE_ROUTED1(PluginMsg_DidFail,
                     unsigned long /* id */)
 
-IPC_MESSAGE_ROUTED4(PluginMsg_SendJavaScriptStream,
+IPC_MESSAGE_ROUTED3(PluginMsg_SendJavaScriptStream,
                     GURL /* url */,
                     std::string /* result */,
-                    bool /* success */,
-                    int /* notify_id */)
+                    bool /* success */)
 
 IPC_MESSAGE_ROUTED2(PluginMsg_DidReceiveManualResponse,
                     GURL /* url */,
                     PluginMsg_DidReceiveResponseParams)
 
 IPC_MESSAGE_ROUTED1(PluginMsg_DidReceiveManualData,
                     std::vector<char> /* buffer */)
 
 IPC_MESSAGE_ROUTED0(PluginMsg_DidFinishManualLoading)
 
 IPC_MESSAGE_ROUTED0(PluginMsg_DidManualLoadFail)
 
-IPC_MESSAGE_ROUTED3(PluginMsg_HandleURLRequestReply,
+IPC_MESSAGE_ROUTED2(PluginMsg_HandleURLRequestReply,
                     unsigned long /* resource_id */,
-                    GURL /* url */,
-                    int /* notify_id */)
+                    GURL /* url */)
 
 IPC_MESSAGE_ROUTED2(PluginMsg_HTTPRangeRequestReply,
                     unsigned long /* resource_id */,
                     int /* range_request_id */)
 
 IPC_MESSAGE_CONTROL1(PluginMsg_SignalModalDialogEvent,
                      int /* render_view_id */)
 
 IPC_MESSAGE_CONTROL1(PluginMsg_ResetModalDialogEvent,
                      int /* render_view_id */)
@@ skipping 198 matching lines @@
 IPC_SYNC_MESSAGE_ROUTED1_2(NPObjectMsg_Construct,
                            std::vector<content::NPVariant_Param> /* args */,
                            content::NPVariant_Param /* result_param */,
                            bool /* result */)
 
 IPC_SYNC_MESSAGE_ROUTED2_2(NPObjectMsg_Evaluate,
                            std::string /* script */,
                            bool /* popups_allowed */,
                            content::NPVariant_Param /* result_param */,
                            bool /* result */)