diff -r 000000000000 -r 6474c204b198 mobile/android/base/tests/PixelTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/tests/PixelTest.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,130 @@
+package org.mozilla.gecko.tests;
+
+import org.mozilla.gecko.Actions;
+import org.mozilla.gecko.PaintedSurface;
+
+abstract class PixelTest extends BaseTest {
+    private static final long PAINT_CLEAR_DELAY = 10000; // milliseconds
+
+    protected final PaintedSurface loadAndGetPainted(String url) {
+        Actions.RepeatedEventExpecter paintExpecter = mActions.expectPaint();
+        inputAndLoadUrl(url);
+        verifyHomePagerHidden();
+        paintExpecter.blockUntilClear(PAINT_CLEAR_DELAY);
+        paintExpecter.unregisterListener();
+        PaintedSurface p = mDriver.getPaintedSurface();
+        if (p == null) {
+            mAsserter.ok(p != null, "checking that painted surface loaded", 
+                 "painted surface loaded");
+        }
+        return p;
+    }
+
+    protected final void loadAndPaint(String url) {
+        PaintedSurface painted = loadAndGetPainted(url);
+        painted.close();
+    }
+
+    protected final PaintedSurface reloadAndGetPainted() {
+        Actions.RepeatedEventExpecter paintExpecter = mActions.expectPaint();
+
+        mActions.sendSpecialKey(Actions.SpecialKey.MENU);
+        waitForText("Reload");
+        mSolo.clickOnText("Reload");
+
+        paintExpecter.blockUntilClear(PAINT_CLEAR_DELAY);
+        paintExpecter.unregisterListener();
+        PaintedSurface p = mDriver.getPaintedSurface();
+        if (p == null) {
+            mAsserter.ok(p != null, "checking that painted surface loaded", 
+                 "painted surface loaded");
+        }
+        return p;
+    }
+
+    protected final void reloadAndPaint() {
+        PaintedSurface painted = reloadAndGetPainted();
+        painted.close();
+    }
+
+    public void addTab(String url, String title, boolean isPrivate) {
+        Actions.EventExpecter tabEventExpecter = mActions.expectGeckoEvent("Tab:Added");
+        Actions.EventExpecter contentEventExpecter = mActions.expectGeckoEvent("DOMContentLoaded");
+        if (isPrivate) {
+            selectMenuItem(StringHelper.NEW_PRIVATE_TAB_LABEL);
+        } else {
+            selectMenuItem(StringHelper.NEW_TAB_LABEL);
+        }
+        tabEventExpecter.blockForEvent();
+        contentEventExpecter.blockForEvent();
+        waitForText(StringHelper.TITLE_PLACE_HOLDER);
+        loadAndPaint(url);
+        tabEventExpecter.unregisterListener();
+        contentEventExpecter.unregisterListener();
+        mAsserter.ok(waitForText(title), "Checking that the page has loaded", "The page has loaded");
+    }
+
+    protected final PaintedSurface waitForPaint(Actions.RepeatedEventExpecter expecter) {
+        expecter.blockUntilClear(PAINT_CLEAR_DELAY);
+        PaintedSurface p = mDriver.getPaintedSurface();
+        if (p == null) {
+            mAsserter.ok(p != null, "checking that painted surface loaded", 
+                 "painted surface loaded");
+        }
+        return p;
+    }
+
+    protected final PaintedSurface waitWithNoPaint(Actions.RepeatedEventExpecter expecter) {
+        try {
+            Thread.sleep(PAINT_CLEAR_DELAY);
+        } catch (InterruptedException ie) {
+            ie.printStackTrace();
+        }
+        mAsserter.is(expecter.eventReceived(), false, "Checking gecko didn't draw unnecessarily");
+        PaintedSurface p = mDriver.getPaintedSurface();
+        if (p == null) {
+            mAsserter.ok(p != null, "checking that painted surface loaded", 
+                 "painted surface loaded");
+        }
+        return p;
+    }
+
+    // this matches the algorithm in robocop_boxes.html
+    protected final int[] getBoxColorAt(int x, int y) {
+        int r = ((int)Math.floor(x / 3) % 256);
+        r = r & 0xF8;
+        int g = (x + y) % 256;
+        g = g & 0xFC;
+        int b = ((int)Math.floor(y / 3) % 256);
+        b = b & 0xF8;
+        return new int[] { r, g, b };
+    }
+
+    /**
+     * Checks the top-left corner of the visible area of the page is at (x,y) of robocop_boxes.html.
+     */
+    protected final void checkScrollWithBoxes(PaintedSurface painted, int x, int y) {
+        int[] color = getBoxColorAt(x, y);
+        mAsserter.ispixel(painted.getPixelAt(0, 0), color[0], color[1], color[2], "Pixel at 0, 0");
+        color = getBoxColorAt(x + 100, y);
+        mAsserter.ispixel(painted.getPixelAt(100, 0), color[0], color[1], color[2], "Pixel at 100, 0");
+        color = getBoxColorAt(x, y + 100);
+        mAsserter.ispixel(painted.getPixelAt(0, 100), color[0], color[1], color[2], "Pixel at 0, 100");
+        color = getBoxColorAt(x + 100, y + 100);
+        mAsserter.ispixel(painted.getPixelAt(100, 100), color[0], color[1], color[2], "Pixel at 100, 100");
+    }
+
+    /**
+     * Loads the robocop_boxes.html file and verifies that we are positioned at (0,0) on it.
+     * @param url URL of the robocop_boxes.html file.
+     * @return The painted surface after rendering the file.
+     */
+    protected final void loadAndVerifyBoxes(String url) {
+        PaintedSurface painted = loadAndGetPainted(url);
+        try {
+            checkScrollWithBoxes(painted, 0, 0);
+        } finally {
+            painted.close();
+        }
+    }
+}