Bug 1516114 - Enable 3-tier PGO for Linux; r=firefox-build-system-reviewers,Callek,chmanchester

Now that 3-tier PGO uses a debian9 image to generate the profile data
(bug 1519424), we no longer see the XDG_RUNTIME_DIR failures in the run
task. The frequency of those errors was the primary blocker for enabling
3-tier PGO in the first place. Since we still see those errors
occasionally in 1-tier PGO, we should switch to the 3-tier model for
Linux.

Differential Revision: https://phabricator.services.mozilla.com/D27326

--HG--
extra : moz-landing-system : lando

taskcluster/ci/build/linux.yml

@@ -798,8 +798,7 @@ linux64-asan/debug:
 
 linux64-shippable/opt:
     description: "Linux64 Shippable"
-    # Disabled because bug 1516114 shows up much more often
-    # use-pgo: true
+    use-pgo: true
     attributes:
         shippable: true
         enable-full-crashsymbols: true
@@ -811,9 +810,7 @@ linux64-shippable/opt:
         type: shippable
     treeherder:
         platform: linux64-shippable/opt
-        # Bug 1516114
-        symbol: B
-        # symbol: Bpgo(B)
+        symbol: Bpgo(B)
     worker-type: aws-provisioner-v1/gecko-{level}-b-linux
     worker:
         max-run-time: 9000
@@ -828,8 +825,7 @@ linux64-shippable/opt:
         secrets: true
         tooltool-downloads: public
         need-xvfb: true
-        # Bug 1516114
-        # mozconfig-variant: profile-use
+        mozconfig-variant: profile-use
     toolchains:
         - linux64-binutils
         - linux64-clang

taskcluster/ci/generate-profile/kind.yml

@@ -22,7 +22,7 @@ job-defaults:
         tier: 1
 
 jobs:
-    linux64/pgo:
+    linux64-shippable/opt:
         description: "Linux64 Profile Generation"
         shipping-phase: build
         shipping-product: firefox
@@ -30,7 +30,7 @@ jobs:
             product: firefox
             job-name: linux64-profile
         treeherder:
-            platform: linux64/pgo
+            platform: linux64-shippable/opt
         worker-type: aws-provisioner-v1/gecko-{level}-b-linux
         worker:
             max-run-time: 1200

taskcluster/ci/instrumented-build/kind.yml

@@ -22,12 +22,12 @@ job-defaults:
         tier: 1
 
 jobs:
-    linux64/pgo:
+    linux64-shippable/opt:
         description: "Linux64 Instrumented"
         shipping-phase: build
         shipping-product: firefox
         treeherder:
-            platform: linux64/pgo
+            platform: linux64-shippable/opt
         worker-type: aws-provisioner-v1/gecko-{level}-b-linux
         worker:
             max-run-time: 7200