Disable hardware acceleration for ChromeActivities on low-end devices.

chrome/android/javatests/src/org/chromium/chrome/browser/hardware_acceleration/Utils.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/hardware_acceleration/Utils.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/hardware_acceleration/Utils.java b/chrome/android/javatests/src/org/chromium/chrome/browser/hardware_acceleration/Utils.java
new file mode 100644
index 0000000000000000000000000000000000000000..0bf5896eb78dd707b7c50828a7bd8b9b39031d4a
--- /dev/null
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/hardware_acceleration/Utils.java
@@ -0,0 +1,75 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.hardware_acceleration;
+
+import android.view.View;
+import android.view.ViewTreeObserver.OnPreDrawListener;
+
+import junit.framework.Assert;
+
+import org.chromium.base.SysUtils;
+import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.content.browser.test.util.CallbackHelper;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Various utils for hardware acceleration tests.
+ */
+public class Utils {
+
+    /**
+     * Asserts that activity is hardware accelerated only on high-end devices.
+     * I.e. on low-end devices hardware acceleration must be off.
+     */
+    public static void assertHardwareAcceleration(final ChromeActivity activity) throws Exception {
+        final AtomicBoolean accelerated = new AtomicBoolean();
+        final CallbackHelper listenerCalled = new CallbackHelper();
+
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                final View view = activity.getWindow().getDecorView();
+                view.getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
+                    @Override
+                    public boolean onPreDraw() {
+                        view.getViewTreeObserver().removeOnPreDrawListener(this);
+                        accelerated.set(view.isHardwareAccelerated());
+                        listenerCalled.notifyCalled();
+                        return true;
+                    }
+                });
+                view.invalidate();
+            }
+        });
+
+        listenerCalled.waitForCallback(0);
+
+        if (SysUtils.isLowEndDevice()) {
+            Assert.assertFalse(accelerated.get());
+        } else {
+            Assert.assertTrue(accelerated.get());
+        }
+    }
+
+    /**
+     * Asserts that there is no thread named 'RenderThread' (which is essential
+     * for hardware acceleration).
+     */
+    public static void assertNoRenderThread() {
+        Assert.assertFalse(collectThreadNames().contains("RenderThread"));
+    }
+
+    private static Set<String> collectThreadNames() {
+        Set<String> names = new HashSet<String>();
+        for (Thread thread : Thread.getAllStackTraces().keySet()) {
+            names.add(thread.getName());
+        }
+        return names;
+    }
+}