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

chrome/browser/ui/android/context_menu_helper.cc

Index: chrome/browser/ui/android/context_menu_helper.cc
diff --git a/chrome/browser/ui/android/context_menu_helper.cc b/chrome/browser/ui/android/context_menu_helper.cc
index 0d677d1e7007e6dc353d104179763c2a70974cda..8313bae0b273dbf7813db4f4b710e5fb47c6d7a8 100644
--- a/chrome/browser/ui/android/context_menu_helper.cc
+++ b/chrome/browser/ui/android/context_menu_helper.cc
@@ -37,6 +37,8 @@ DEFINE_WEB_CONTENTS_USER_DATA_KEY(ContextMenuHelper);
 const char kDataReductionProxyPassthroughHeader[] =
     "Chrome-Proxy-Accept-Transform: identity\r\n";
 
+const bool kUsePNGCodec = true;
+
 namespace {
 
 void OnRetrieveImage(chrome::mojom::ThumbnailCapturerPtr thumbnail_capturer,
@@ -176,7 +178,7 @@ void ContextMenuHelper::RetrieveImage(JNIEnv* env,
   // there's either a connection error or a response.
   auto* thumbnail_capturer_proxy = thumbnail_capturer.get();
   thumbnail_capturer_proxy->RequestThumbnailForContextNode(
-      0, gfx::Size(max_dimen_px, max_dimen_px),
+      0, gfx::Size(max_dimen_px, max_dimen_px), kUsePNGCodec,
       base::Bind(&OnRetrieveImage, base::Passed(&thumbnail_capturer),
                  base::android::ScopedJavaGlobalRef<jobject>(env, jcallback)));
 }