Re-enable image capture tests on Windows

Image capture tests were disabled since issue 633242.
We think this was caused by the fact that bots were running webcam tests
concurrently.
Now that concurrency has been disabled for these tests on Windows, they
should pass.

Bug: 806431
Change-Id: Ic836752abef240d622f13cc7c44883540e033cf7
Reviewed-on: https://chromium-review.googlesource.com/890518Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Commit-Queue: Christian Fremerey <chfremer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532992}

content/browser/webrtc/webrtc_image_capture_browsertest.cc

@@ -23,16 +23,7 @@
 
 namespace content {
 
-#if defined(OS_WIN)
-// These tests are flaky on WebRTC Windows bots: https://crbug.com/633242.
-#define MAYBE_GetPhotoCapabilities DISABLED_GetPhotoCapabilities
-#define MAYBE_GetPhotoSettings DISABLED_GetPhotoSettings
-#define MAYBE_TakePhoto DISABLED_TakePhoto
-#define MAYBE_GrabFrame DISABLED_GrabFrame
-#define MAYBE_GetTrackCapabilities DISABLED_GetTrackCapabilities
-#define MAYBE_GetTrackSettings DISABLED_GetTrackSettings
-#define MAYBE_ManipulateZoom DISABLED_ManipulateZoom
-#elif defined(OS_ANDROID)
+#if defined(OS_ANDROID)
 // TODO(chfremer): Re-enable test on Android as soon as the cause for
 // https://crbug.com/793859 is understood and fixed.
 #define MAYBE_GetPhotoCapabilities GetPhotoCapabilities