Fixing transparent pixels appearing black when rendered for the context menu.

chrome/browser/ui/tab_contents/core_tab_helper.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.
 
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 101 matching lines @@
     content::RenderFrameHost* render_frame_host,
     const GURL& src_url) {
   chrome::mojom::ThumbnailCapturerPtr thumbnail_capturer;
   render_frame_host->GetRemoteInterfaces()->GetInterface(&thumbnail_capturer);
   // Bind the InterfacePtr into the callback so that it's kept alive until
   // there's either a connection error or a response.
   auto* thumbnail_capturer_proxy = thumbnail_capturer.get();
   thumbnail_capturer_proxy->RequestThumbnailForContextNode(
       kImageSearchThumbnailMinSize,
       gfx::Size(kImageSearchThumbnailMaxWidth, kImageSearchThumbnailMaxHeight),
+      chrome::mojom::ImageFormat::JPEG,
       base::Bind(&CoreTabHelper::DoSearchByImageInNewTab,
                  weak_factory_.GetWeakPtr(), base::Passed(&thumbnail_capturer),
                  src_url));
 }
 
 // static
 bool CoreTabHelper::GetStatusTextForWebContents(
     base::string16* status_text, content::WebContents* source) {
   // TODO(robliao): Remove ScopedTracker below once https://crbug.com/467185 is
   // fixed.
@@ skipping 214 matching lines @@
     DCHECK(!content_type.empty());
     open_url_params.uses_post = true;
     open_url_params.post_data = content::ResourceRequestBody::CreateFromBytes(
         post_data.data(), post_data.size());
     open_url_params.extra_headers += base::StringPrintf(
         "%s: %s\r\n", net::HttpRequestHeaders::kContentType,
         content_type.c_str());
   }
   web_contents()->OpenURL(open_url_params);
 }