Removed duplicated JS hasVideoInputDeviceOnSystem() test helper

content/public/test/browser_test_utils.cc

Index: content/public/test/browser_test_utils.cc
diff --git a/content/public/test/browser_test_utils.cc b/content/public/test/browser_test_utils.cc
index 802d4eba324aefe2afe3628832346c879ff54346..64b6aa924a934308f6ecc49cde5580ba61ae115d 100644
--- a/content/public/test/browser_test_utils.cc
+++ b/content/public/test/browser_test_utils.cc
@@ -408,6 +408,25 @@ void AppendGzippedResource(const base::RefCountedMemory& encoded,
   } while (status != net::Filter::FILTER_DONE);
 }
 
+// Queries for video input devices on the current system using the getSources
+// API.
+//
+// This does not guarantee that a getUserMedia with video will succeed, as the
+// camera could be busy for instance.
+//
+// Returns has-video-input-device to the test if there is a webcam available,
+// no-video-input-devices otherwise.
+static const std::string hasVideoInputDeviceOnSystem =
+    "(function() {"
+      "MediaStreamTrack.getSources(function(devices) {"
+        "devices.forEach(function(device) {"
+          "if (device.kind == 'video')"
+            "returnToTest('has-video-input-device');"

[mcasas, 2016/09/06 23:13:12]

returnToTest(), confusingly enough, doesn't
seem to return. This code could returnToTest
a 'has-video-input-device' and then subsequently a
'no-video-input-devices', if e.g. the bot would 
have a webcam and another audio device. IOW you
need a return statement here.

Also please add a TODO and a bug saying that 
this needs to be migrated to Navigator.mediaDevices(),
since MediaStreamTrack.getSources() is deprecated
(https://www.chromestatus.com/feature/4906859072847872).

[lunalu1, 2016/09/07 14:30:34]

Done.

+        "});"
+        "returnToTest('no-video-input-devices');"
+      "});"
+    "})()";
+
 }  // namespace
 
 bool NavigateIframeToURL(WebContents* web_contents,
@@ -742,6 +761,13 @@ void SimulateKeyPress(WebContents* web_contents,
   ASSERT_EQ(modifiers, 0);
 }
 
+bool HasWebcamAvailableOnSystem(WebContents* tab_contents) {
+  std::string result;
+  EXPECT_TRUE(content::ExecuteScriptAndExtractString(
+      tab_contents, hasVideoInputDeviceOnSystem, &result));
+  return result == "has-video-input-device";
+}
+
 RenderFrameHost* ConvertToRenderFrameHost(WebContents* web_contents) {
   return web_contents->GetMainFrame();
 }