diff --git a/testing/talos/talos.json b/testing/talos/talos.json
index 5a2c164e2d9a..914c66d37587 100644
--- a/testing/talos/talos.json
+++ b/testing/talos/talos.json
@@ -47,7 +47,7 @@
             "talos_options": ["--disable-stylo"]
         },
         "g4-e10s": {
-            "tests": ["basic_compositor_video", "glvideo", "displaylist_mutate", "rasterflood_svg"]
+            "tests": ["basic_compositor_video", "glvideo", "displaylist_mutate", "rasterflood_svg", "rasterflood_gradient"]
         },
         "g4-stylo-disabled-e10s": {
             "tests": ["basic_compositor_video", "glvideo"],
diff --git a/testing/talos/talos/test.py b/testing/talos/talos/test.py
index 40a29bb18331..9bb34922893e 100644
--- a/testing/talos/talos/test.py
+++ b/testing/talos/talos/test.py
@@ -986,3 +986,26 @@ class rasterflood_svg(PageloaderTest):
                    'docshell.event_starvation_delay_hint': 1,
                    'dom.send_after_paint_to_content': False}
     unit = 'ms'
+
+
+@register_test()
+class rasterflood_gradient(PageloaderTest):
+    """
+    Test expensive rasterization while the main thread is busy.
+    """
+    tpmanifest = '${talos}/tests/gfx/rasterflood_gradient.manifest'
+    tpcycles = 1
+    tppagecycles = 10
+    tploadnocache = True
+    tpmozafterpaint = False
+    tpchrome = False
+    gecko_profile_interval = 2
+    gecko_profile_entries = 2000000
+    win_counters = w7_counters = linux_counters = mac_counters = None
+    filters = filter.ignore_first.prepare(1) + filter.median.prepare()
+    """ASAP mode"""
+    preferences = {'layout.frame_rate': 0,
+                   'docshell.event_starvation_delay_hint': 1,
+                   'dom.send_after_paint_to_content': False}
+    lower_is_better = False
+    unit = 'score'
diff --git a/testing/talos/talos/tests/gfx/benchmarks/rasterflood_gradient.html b/testing/talos/talos/tests/gfx/benchmarks/rasterflood_gradient.html
new file mode 100644
index 000000000000..778c8b475cfc
--- /dev/null
+++ b/testing/talos/talos/tests/gfx/benchmarks/rasterflood_gradient.html
@@ -0,0 +1,132 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
+  <title>Paint-In-Time 2</title>
+  <style>
+    .gradient {
+      position: absolute;
+      width: 800px;
+      height: 600px;
+      opacity: 0.4;
+    }
+  </style>
+</head>
+<body>
+  <div id="grid">
+  </div>
+</body>
+<script>
+
+// Only allow painting a tiny slice of the frame - here, 15ms.
+var kFrameBudgetMs = 14;
+var kDivCount = 10;
+var kMaxTime = 20 * 1000;
+
+var gCrazyCounter = 0;
+var gIterations = 0;
+var gStart;
+var gDivs = [];
+
+function GetColor()
+{
+  var color = GetColor.kColors[GetColor.Index];
+  GetColor.Index++;
+  GetColor.Index = (GetColor.Index % GetColor.kColors.length);
+  return color;
+}
+GetColor.Index = 0;
+GetColor.kColors = ["red", "white", "green", "yellow", "orange", "brown"];
+
+function RadialGradient(offset)
+{
+  this.colors = [GetColor(), GetColor()];
+  this.percents = [0 + offset, 20 + offset];
+  this.toStyle = function() {
+    return "radial-gradient(" +
+      this.colors[0] + " " + this.percents[0] + "%, " +
+      this.colors[1] + " " + this.percents[1] + "%)";
+  };
+  this.advance = function() {
+    this.percents[0] += 1;
+    this.percents[0] %= 80;
+    this.percents[1] = this.percents[0] + 20;
+  };
+}
+
+function runFrame()
+{
+  var start = performance.now();
+
+  // Spin loop.
+  while (performance.now() - start < kFrameBudgetMs)
+    gCrazyCounter++;
+
+  for (var i = 0; i < gDivs.length; i++) {
+    var info = gDivs[i];
+    info.gradient.advance();
+    info.element.style.background = info.gradient.toStyle();
+  }
+
+  gIterations++;
+
+  if (performance.now() - gStart >= kMaxTime) {
+    if (window.tpRecordTime) {
+      window.tpRecordTime(gIterations);
+    }
+    return;
+  }
+
+  window.requestAnimationFrame(runFrame);
+}
+
+function setup()
+{
+  var root = document.getElementById("grid");
+  for (var i = 0; i < kDivCount; i++) {
+    var gradient = new RadialGradient(i * 10 / 2);
+
+    var div = document.createElement("div");
+    var info = {
+      element: div,
+      gradient: gradient
+    };
+
+    div.classList.add("gradient");
+    div.style.left = "10px";
+    div.style.top = "10px";
+    div.style.background = gradient.toStyle();
+    root.appendChild(div);
+
+    gDivs.push(info);
+  }
+}
+
+function startTest() {
+  setup();
+  gStart = performance.now();
+  window.requestAnimationFrame(runFrame);
+}
+
+addEventListener("load", function() {
+  try {
+    // Outside of talos, this throws a security exception which no-op this file.
+    // (It's not required nor allowed for addons since Firefox 17)
+    // It's used inside talos from non-privileged pages (like during tscroll),
+    // and it works because talos disables all/most security measures.
+    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
+  } catch (e) {}
+
+  try {
+    Components.utils.import("resource://gre/modules/Services.jsm");
+    Services.scriptloader.loadSubScript("chrome://talos-powers-content/content/TalosContentProfiler.js");
+
+    TalosContentProfiler.resume("rasterflood_gradient.html loaded", true).then(() => {
+      startTest();
+    });
+  } catch (e) {
+    startTest();
+  }
+});
+</script>
+</html>
diff --git a/testing/talos/talos/tests/gfx/rasterflood_gradient.manifest b/testing/talos/talos/tests/gfx/rasterflood_gradient.manifest
new file mode 100644
index 000000000000..2351c5653f76
--- /dev/null
+++ b/testing/talos/talos/tests/gfx/rasterflood_gradient.manifest
@@ -0,0 +1 @@
+% http://localhost/tests/gfx/benchmarks/rasterflood_gradient.html
