Media Controls: Remove download button for infinite streams

third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

Index: third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
index bb6da9e90b6f07dac88e6b7814d3c747a9f3e176..567a7a7586c5d42f09d9217ab8a3fbba13960162 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
@@ -679,7 +679,7 @@ bool MediaControlDownloadButtonElement::shouldDisplayDownloadButton() {
   if (url.isNull() || url.isEmpty())
     return false;
 
-  // Local files and blobs should not have a download button.
+  // Local files and blobs (including MSE) should not have a download button.
   if (url.isLocalFile() || url.protocolIs("blob"))
     return false;
 
@@ -695,6 +695,11 @@ bool MediaControlDownloadButtonElement::shouldDisplayDownloadButton() {
   if (HTMLMediaElement::isHLSURL(url))
     return false;
 
+  // Infinite streams don't have a clear end at which to finish the download
+  // (would require adding UI to prompt for the duration to download).
+  if (mediaElement().duration() == std::numeric_limits<double>::infinity())
+    return false;
+
   return true;
 }