Added Tab.SnapshotContent and MapsGL example to telemetry

tools/telemetry/telemetry/inspector_page_unittest.py

Index: tools/telemetry/telemetry/inspector_page_unittest.py
diff --git a/tools/telemetry/telemetry/inspector_page_unittest.py b/tools/telemetry/telemetry/inspector_page_unittest.py
index 33c476e5d76d4de9c1aaba430aab5783bf1ebc2a..f7c1a101624d7d6a19f596affd5863da54bd526e 100644
--- a/tools/telemetry/telemetry/inspector_page_unittest.py
+++ b/tools/telemetry/telemetry/inspector_page_unittest.py
@@ -24,6 +24,18 @@ class InspectorPageTest(tab_test_case.TabTestCase):
     self._tab.page.Navigate('http://23f09f0f9fsdflajsfaldfkj2f3f.com')
     self._tab.WaitForDocumentReadyStateToBeComplete()
 
+  def testScreenshot(self):
+    unittest_data_dir = os.path.join(os.path.dirname(__file__),

[nduca, 2012/11/12 19:53:26]

What happens if we run this on an old browser? E.g. ./run_tests --browser=system
...

The test is gonna fail. :(

You'll want to have this test early return if the screenshot feature isn't
supported.

Which might mean you should have a IsScreenshotSupported() method on page.

+                                     '..', 'unittest_data')
+    self._browser.SetHTTPServerDirectory(unittest_data_dir)
+    self._tab.page.Navigate(
+      self._browser.http_server.UrlOf('green_page.html'))
+    self._tab.WaitForDocumentReadyStateToBeComplete()
+    screenshot = self._tab.page.Screenshot()
+    self.assertTrue(screenshot.GetPixelColor(0, 0).CheckRGB(0, 255, 0))
+    self.assertTrue(screenshot.GetPixelColor(32, 32).CheckRGB(0, 255, 0))
+    self.assertTrue(screenshot.GetPixelColor(33, 33).CheckRGB(255, 255, 255))
+
   def testCustomActionToNavigate(self):
     unittest_data_dir = os.path.join(os.path.dirname(__file__),
                                      '..', 'unittest_data')