LUCI buckets: make cores:8 default

Update luci.chromium.{ci,try} defaults to use "cores:8" dimension.
Update builders and mixins not to specify default values for cores, cpu
and pool dimensions.

Update some Mac GPU/Angle builders and mixins to use cores:4 or clear
cores requirement because we have 4-core or a mix of 4-core and 8-core
Macs.

R=dpranke@chromium.org, kbr@chromium.org, tandrii@chromium.org
No-Try: true

Change-Id: I370a004c2c07e450a6c1426e5f7419b00d882536
Reviewed-on: https://chromium-review.googlesource.com/970907Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544716}

infra/config/global/cr-buildbucket.cfg

@@ -121,24 +121,18 @@ builder_mixins {
 
 builder_mixins {
   name: "android-angle-try"
-  dimensions: "cores:8"
-  dimensions: "cpu:x86-64"
   dimensions: "os:Ubuntu-14.04"
   mixins: "angle-try"
 }
 
 builder_mixins {
   name: "android-gpu-fyi-ci"
-  dimensions: "cores:8"
-  dimensions: "cpu:x86-64"
   dimensions: "os:Ubuntu-14.04"
   mixins: "gpu-fyi-ci"
 }
 
 builder_mixins {
   name: "android-optional-gpu-try"
-  dimensions: "cores:8"
-  dimensions: "cpu:x86-64"
   dimensions: "os:Ubuntu-14.04"
   mixins: "gpu-optional-try"
   mixins: "android-try"
@@ -219,8 +213,6 @@ builder_mixins {
 
 builder_mixins {
   name: "linux-gpu-fyi-ci"
-  dimensions: "cpu:x86-64"
-  dimensions: "cores:8"
   mixins: "linux"
   mixins: "gpu-fyi-ci"
 }
@@ -234,6 +226,7 @@ builder_mixins {
   name: "mac-angle-try"
   mixins: "mac"
   mixins: "angle-try"
+  dimensions: "cores:4"
 }
 
 builder_mixins {
@@ -263,9 +256,9 @@ builder_mixins {
 
 builder_mixins {
   name: "mac-gpu-fyi-ci"
-  dimensions: "cpu:x86-64"
   mixins: "mac"
   mixins: "gpu-fyi-ci"
+  dimensions: "cores:4"
 }
 
 builder_mixins {
@@ -307,7 +300,6 @@ builder_mixins {
 
 builder_mixins {
   name: "win-gpu-fyi-ci"
-  dimensions: "cpu:x86-64"
   mixins: "win"
   mixins: "gpu-fyi-ci"
   mixins: "gpu-slow-bot"
@@ -330,8 +322,8 @@ buckets {
   swarming {
     hostname: "chromium-swarm.appspot.com"
     builder_defaults {
+      dimensions: "cores:8"
       dimensions: "cpu:x86-64"
-      dimensions: "pool:luci.chromium.ci"
       service_account: "chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
       execution_timeout_secs: 10800  # 3h
       swarming_tags: "vpython:native-python-wrapper"
@@ -356,7 +348,6 @@ buckets {
       name: "Android arm64 Builder (dbg)"
       mixins: "android-ci"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
       execution_timeout_secs: 14400  # 4h
     }
 
@@ -409,7 +400,6 @@ buckets {
       name: "Android x64 Builder (dbg)"
       mixins: "android-ci"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
       execution_timeout_secs: 14400  # 4h
     }
 
@@ -417,14 +407,12 @@ buckets {
       name: "Android x86 Builder (dbg)"
       mixins: "android-ci"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
     }
 
     builders {
       name: "Marshmallow 64 bit Tester"
       mixins: "android-ci"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
     }
 
     # Fuchsia bots.
@@ -472,7 +460,6 @@ buckets {
     builders {
       name: "GPU Linux Builder"
       mixins: "linux-gpu-ci"
-      dimensions: "cores:8"
     }
 
     builders {
@@ -491,7 +478,6 @@ buckets {
     builders {
       name: "Linux Release (NVIDIA)"
       mixins: "linux-gpu-ci"
-      dimensions: "cores:8"
     }
 
     builders {
@@ -502,22 +488,18 @@ buckets {
     builders {
       name: "Linux Builder (dbg)"
       mixins: "linux-ci"
-      dimensions: "cpu:x86-64"
       dimensions: "cores:32"
     }
 
     builders {
       name: "Linux Builder (dbg)(32)"
       mixins: "linux-ci"
-      dimensions: "cpu:x86-64"
       dimensions: "cores:32"
     }
 
     builders {
       name: "Linux Tests (dbg)(1)"
       mixins: "linux-ci"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
 
     builders {
@@ -580,14 +562,10 @@ buckets {
     builders {
       name: "Mac Builder (dbg)"
       mixins: "mac-ci"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
     builders {
       name: "Mac10.13 Tests (dbg)"
       mixins: "mac-ci"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
 
     # chromium.gpu.fyi
@@ -662,35 +640,27 @@ buckets {
     builders {
       name: "Win Builder"
       mixins: "win-ci"
-      dimensions: "cpu:x86-64"
       dimensions: "cores:32"
     }
     builders {
       name: "Win Builder (dbg)"
       mixins: "win-ci"
-      dimensions: "cpu:x86-64"
       dimensions: "cores:32"
     }
     builders {
       name: "Win7 (32) Tests"
       mixins: "win-ci"
       dimensions: "os:Windows-7"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
     builders {
       name: "Win7 Tests (1)"
       mixins: "win-ci"
       dimensions: "os:Windows-7"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
     builders {
       name: "Win7 Tests (dbg)(1)"
       mixins: "win-ci"
       dimensions: "os:Windows-7"
-      dimensions: "cpu:x86-64"
-      dimensions: "cores:8"
     }
     builders {
       name: "Win10 Tests x64 (dbg)"
@@ -702,37 +672,30 @@ buckets {
     builders {
       name: "GPU FYI Win Builder"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win Builder (dbg)"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win Clang Builder (dbg)"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win dEQP Builder"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win x64 Builder"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win x64 Builder (dbg)"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "GPU FYI Win x64 dEQP Builder"
       mixins: "win-gpu-fyi-ci"
-      dimensions: "cores:8"
     }
     builders {
       name: "Win10 FYI Debug (NVIDIA)"
@@ -852,8 +815,8 @@ buckets {
 
     builder_defaults {
       category: "Chromium CQ"
+      dimensions: "cores:8"
       dimensions: "cpu:x86-64"
-      dimensions: "pool:luci.chromium.try"
       service_account: "chromium-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       execution_timeout_secs: 10800  # 3h
       swarming_tags: "vpython:native-python-wrapper"
@@ -881,13 +844,11 @@ buckets {
       mixins: "android-try"
       name: "android_arm64_dbg_recipe"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
     }
     builders {
       mixins: "android-try"
       name: "android_n5x_swarming_dbg"
       dimensions: "os:Ubuntu-14.04"
-      dimensions: "cores:8"
     }
     builders { mixins: "android-optional-gpu-try" name: "android_optional_gpu_tests_rel" }
 
@@ -1022,7 +983,12 @@ buckets {
     builders { mixins: "mac-try" name: "mac_chromium_variable_layout" }
     builders { mixins: "mac-try" name: "mac_nacl_sdk" }
     builders { mixins: "mac-try" name: "mac_nacl_sdk_build" }
-    builders { mixins: "mac-optional-gpu-try" name: "mac_optional_gpu_tests_rel" }
+    builders {
+      mixins: "mac-optional-gpu-try"
+      name: "mac_optional_gpu_tests_rel"
+      # Clear cores dimension requirement because build{103..105}-m9 are cores:4
+      dimensions: "cores:"
+    }
     builders { mixins: "mac-try" name: "mac_upload_clang" }
     builders { mixins: "mac-try" name: "mac-views-rel" }