Raise an infobar and deny access to WebGL if a GPU reset was detected while a web page containing W…

content/test/data/gpu/webgl.html

Index: content/test/data/gpu/webgl.html
diff --git a/content/test/data/gpu/webgl.html b/content/test/data/gpu/webgl.html
index 928fae7d760eeacda49cb318c731db084ee7da81..38e3fab08c19c628168a5823cdd5f1373135d020 100644
--- a/content/test/data/gpu/webgl.html
+++ b/content/test/data/gpu/webgl.html
@@ -39,7 +39,7 @@ function testContextLost(e) {
 function testContextRestored() {
   gl = canvas.getContext("experimental-webgl");
   if (!gl || gl.isContextLost()) {
-    document.title = "FAILED: could not get recovered context";
+    // Might just be blocked because of infobar.
     return;
   }
   gl.clearColor(0, 0, 1, 1);