headless: Enable GL support by default

headless/lib/headless_browser_browsertest.cc

Index: headless/lib/headless_browser_browsertest.cc
diff --git a/headless/lib/headless_browser_browsertest.cc b/headless/lib/headless_browser_browsertest.cc
index a6bbc8bf52db9030098ca541eaf92b5428ad485b..75ae5133006aef82ba6f7c8568817cf9c256f47c 100644
--- a/headless/lib/headless_browser_browsertest.cc
+++ b/headless/lib/headless_browser_browsertest.cc
@@ -159,4 +159,19 @@ IN_PROC_BROWSER_TEST_F(HeadlessBrowserTest, HttpsProtocolHandler) {
   EXPECT_EQ(kResponseBody, inner_html);
 }
 
+IN_PROC_BROWSER_TEST_F(HeadlessBrowserTest, WebGLSupported) {
+  HeadlessWebContents* web_contents =
+      browser()->CreateWebContentsBuilder().Build();
+
+  bool webgl_supported;
+  EXPECT_TRUE(EvaluateScript(
+      web_contents,
+      "(document.createElement('canvas').getContext('webgl')"
+      "    instanceof WebGLRenderingContext)")
+                  ->GetResult()
+                  ->GetValue()
+                  ->GetAsBoolean(&webgl_supported));
+  EXPECT_TRUE(webgl_supported);
+}
+
 }  // namespace headless