Mark Win7 GPU bots slow.

These bots had a 3h timeout specified manually, where the rest of the
bots on the chromium.gpu.fyi waterfall which use the win-gpu-fyi-ci
mixin pick up the gpu-slow-bot specification automatically, which
provides a 6h timeout. Remove the manual execution_timeout_secs for
these bots while Issue 917211 is being investigated.

Bug: 928303
Change-Id: I8c4bd12e8b06c6391a5ed2ea4f4d15ab16111e02
Reviewed-on: https://chromium-review.googlesource.com/c/1453058
Auto-Submit: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#628918}
diff --git a/infra/config/global/cr-buildbucket.cfg b/infra/config/global/cr-buildbucket.cfg
index b8e06419..104a7480a 100644
--- a/infra/config/global/cr-buildbucket.cfg
+++ b/infra/config/global/cr-buildbucket.cfg
@@ -1894,17 +1894,14 @@
     builders {
       name: "Win7 FYI Release (NVIDIA)"
       mixins: "win-gpu-fyi-ci"
-      execution_timeout_secs: 10800  # 3h
     }
     builders {
       name: "Win7 FYI x64 dEQP Release (NVIDIA)"
       mixins: "win-gpu-fyi-ci"
-      execution_timeout_secs: 10800  # 3h
     }
     builders {
       name: "Win7 FYI x64 Release (NVIDIA)"
       mixins: "win-gpu-fyi-ci"
-      execution_timeout_secs: 10800  # 3h
     }
 
     # Code coverage reports generation bots.