Media Galleries: Fix render-process-gone case in GetMetadata call

chrome/browser/extensions/api/media_galleries/media_galleries_api.cc

 // Copyright (c) 2012 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.
 
 // Implements the Chrome Extensions Media Galleries API.
 
 #include "chrome/browser/extensions/api/media_galleries/media_galleries_api.h"
 
 #include <stddef.h>
 
@@ skipping 734 matching lines @@
       new base::DictionaryValue);
   attached_image->Set(kBlobUUIDKey, new base::StringValue(
       current_blob->GetUUID()));
   attached_image->Set(kTypeKey, new base::StringValue(
       current_image->type));
   attached_image->Set(kSizeKey, new base::FundamentalValue(
       base::checked_cast<int>(current_image->data.size())));
   attached_images_list->Append(std::move(attached_image));
 
   blob_uuids->push_back(current_blob->GetUUID());
+
+  content::RenderProcessHost* render_process_host =
+      render_frame_host()->GetProcess();
+  if (!render_process_host) {
+    SendResponse(false);
+    return;
+  }
+
   extensions::BlobHolder* holder =
-      extensions::BlobHolder::FromRenderProcessHost(
-          render_frame_host()->GetProcess());
+      extensions::BlobHolder::FromRenderProcessHost(render_process_host);
   holder->HoldBlobReference(std::move(current_blob));
 
   // Construct the next Blob if necessary.
   if (blob_uuids->size() < attached_images->size()) {
     metadata::AttachedImage* next_image =
         &(*attached_images)[blob_uuids->size()];
     content::BrowserContext::CreateMemoryBackedBlob(
         GetProfile(),
         next_image->data.c_str(),
         next_image->data.size(),
@@ skipping 133 matching lines @@
     SendResponse(false);
     return;
   }
 
   gallery_watch_manager()->RemoveWatch(
       GetProfile(), extension_id(), gallery_pref_id);
   SendResponse(true);
 }
 
 }  // namespace extensions