Disable rendering.desktop/camera_to_webgl on linux

Disabling failing perf test rendering.desktop/camera_to_webgl on Linux.

TBR=crouleau@chromium.org
NOTRY=true

Bug: 1026788
Change-Id: I33855a286f0391630291ecfd8a78d31de53a61cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1925262
Commit-Queue: John Chen <johnchen@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#717246}

tools/perf/expectations.config

@@ -222,6 +222,7 @@ crbug.com/755556 [ mac ] rendering.desktop/mix_blend_mode_animation_difference [
 crbug.com/755556 [ mac ] rendering.desktop/mix_blend_mode_animation_hue [ Skip ]
 crbug.com/1017244 [ desktop ] rendering.desktop/youtube_2018 [ Skip ]
 crbug.com/1017244 [ desktop ] rendering.desktop/youtube_pinch_2018 [ Skip ]
+crbug.com/1026788 [ linux ] rendering.desktop/camera_to_webgl [ Skip ]
 
 # Benchmark: rendering.mobile
 crbug.com/785485 [ android-webview ] rendering.mobile/kevs_3d [ Skip ]