Currently WebContentsImpl::onDownloadImageFinished() passes the downloaded bitmap through JNI synchronously, which keeps both the native bitmap and Java bitmap on the stack, which increases the memory pressure.

Since WebContents::DownloadImage() is already async, we can post a task to notify that the image has been downloaded to reduce the memory pressure.
 

Currently WebContentsImpl::onDownloadImageFinished() passes the downloaded bitmap through JNI synchronously, which keeps both the native bitmap and Java bitmap on the stack, which increases the memory pressure. If the user then does memory-heavy jobs on the callback, it will have higher chance to hit OOMs.

Since WebContents::DownloadImage() is already async, we can post a task to notify that the image has been downloaded to reduce the memory pressure.