Revert of Switch to use SequencedTaskChecker instead of ThreadChecker where needed. (patchset #1 id:1 of https://codereview.webrtc.org/2149553002/ )

Reason for revert:
Breaks Chrome FYI

https://build.chromium.org/p/chromium.webrtc.fyi/builders/Linux%20Builder/builds/8187/steps/compile/logs/stdio

Original issue's description:
> Switch to use SequencedTaskChecker instead of ThreadChecker where needed.
> This cl is in preparation for https://codereview.webrtc.org/2060403002/ Add task queue to Call.
> In the coming cl the video_sender, and i420_buffer_pool will be used on a task queue and therefore SequencedTaskChecker is needed instead of a ThreadChecker.
>
> BUG=webrtc:5687
>
> Committed: https://crrev.com/ec7cef854d85be2d9fd5b1a4e2c59a67feb662eb
> Cr-Commit-Position: refs/heads/master@{#13474}

TBR=tommi@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5687

Review-Url: https://codereview.webrtc.org/2150843003
Cr-Commit-Position: refs/heads/master@{#13475}

webrtc/modules/video_coding/video_coding.gypi

@@ -14,7 +14,6 @@
       'dependencies': [
         'webrtc_h264',
         'webrtc_i420',
-        '../base/base.gyp:rtc_task_queue',
         '<(webrtc_root)/common_video/common_video.gyp:common_video',
         '<(webrtc_root)/modules/video_coding/utility/video_coding_utility.gyp:video_coding_utility',
         '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers',