Revert "Enable UsingRealWebcam_* test on ChromeOS"

This reverts commit a420f12c.

Reason for revert: causing failure on chromeos-amd64-generic-rel bot. (crbug.com/1127015)

Original change's description:
> Enable UsingRealWebcam_* test on ChromeOS
>
> Bug: 1069608
> Test: Pass 'tast --verbose run <betty> "camera.CaptureUnittests"' 15
> times in a row.
>
> Change-Id: I30d6872ad9a6d30a41cc14648a12d71a1fed274a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387911
> Commit-Queue: Inker Kuo <inker@chromium.org>
> Auto-Submit: Inker Kuo <inker@chromium.org>
> Reviewed-by: Shik Chen <shik@chromium.org>
> Reviewed-by: Guido Urdaneta <guidou@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#804650}

TBR=shik@chromium.org,guidou@chromium.org,inker@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1069608, 1127015
Change-Id: I850771baa03d86fc5bb03e87fd1151eb6fefa167
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404266Reviewed-by: Mitsuru Oshima (Slow: gardener) <oshima@chromium.org>
Commit-Queue: Mitsuru Oshima (Slow: gardener) <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805873}

media/capture/video/video_capture_device_unittest.cc

@@ -97,9 +97,13 @@
 #define MAYBE_UsingRealWebcam_AllocateBadSize \
   DISABLED_UsingRealWebcam_AllocateBadSize
 #define MAYBE_UsingRealWebcam_CaptureMjpeg UsingRealWebcam_CaptureMjpeg
-#define MAYBE_UsingRealWebcam_TakePhoto UsingRealWebcam_TakePhoto
-#define MAYBE_UsingRealWebcam_GetPhotoState UsingRealWebcam_GetPhotoState
-#define MAYBE_UsingRealWebcam_CaptureWithSize UsingRealWebcam_CaptureWithSize
+// Flaky: https://crbug.com/1096082
+#define MAYBE_UsingRealWebcam_TakePhoto DISABLED_UsingRealWebcam_TakePhoto
+#define MAYBE_UsingRealWebcam_GetPhotoState \
+  DISABLED_UsingRealWebcam_GetPhotoState
+// Flaky crash: https://crbug.com/1069608
+#define MAYBE_UsingRealWebcam_CaptureWithSize \
+  DISABLED_UsingRealWebcam_CaptureWithSize
 #define MAYBE_UsingRealWebcam_CheckPhotoCallbackRelease \
   UsingRealWebcam_CheckPhotoCallbackRelease
 #elif defined(OS_LINUX)