[gn] Fix valgrind config

BUG=chromium:474921
NOTRY=true
NOTREECHECKS=true
TBR=vogelheim@chromium.org, jochen@chromium.org

Review-Url: https://codereview.chromium.org/2109403002
Cr-Commit-Position: refs/heads/master@{#37418}

BUILD.gn

@@ -44,6 +44,10 @@ declare_args() {
   # Enable slow dchecks.
   v8_enable_slow_dchecks = false
 
+  # Indicate if valgrind was fetched as a custom deps to make it available on
+  # swarming.
+  v8_has_valgrind = false
+
   # Interpreted regexp engine exists as platform-independent alternative
   # based where the regular expression is compiled to a bytecode.
   v8_interpreted_regexp = false

gni/isolate.gni

@@ -101,6 +101,11 @@ template("v8_isolate_run") {
       } else {
         use_snapshot = "false"
       }
+      if (v8_has_valgrind) {
+        has_valgrind = "1"
+      } else {
+        has_valgrind = "0"
+      }
 
       # Note, all paths will be rebased in isolate_driver.py to be relative to
       # the isolate file.
@@ -132,7 +137,7 @@ template("v8_isolate_run") {
         "--config-variable",
         "gcmole=0",
         "--config-variable",
-        "has_valgrind=0",
+        "has_valgrind=$has_valgrind",
         "--config-variable",
         "icu_use_data_file_flag=$icu_use_data_file_flag",
         "--config-variable",

infra/mb/mb_config.pyl

@@ -544,8 +544,7 @@
     },
 
     'valgrind': {
-      # TODO(machenbach): Add this to gn.
-      'gn_args': 'has_valgrind=true',
+      'gn_args': 'v8_has_valgrind=true',
       'gyp_defines': 'has_valgrind=1',
     },