Enable DCHECKS for blink-heap-verification bot.

Bug: 817779
Change-Id: If4599943937ea5c628bfc3cc96f5df9b9b4065f1
Reviewed-on: https://chromium-review.googlesource.com/959345Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Benjamin Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542578}

tools/mb/mb_config.pyl

@@ -242,7 +242,7 @@
       'Linux Xenial': 'release_bot',
       'linux-annotator-rel': 'release_bot',
       'linux-blink-heap-incremental-marking': 'debug_bot_enable_blink_heap_incremental_marking',
-      'linux-blink-heap-verification': 'release_bot_enable_blink_heap_verification',
+      'linux-blink-heap-verification': 'release_bot_enable_blink_heap_verification_dcheck_always_on',
       'Mac deterministic': 'release_bot_mac_strip',
       'Mac deterministic (dbg)': 'debug_bot',
       'Mojo ChromiumOS': 'chromeos_with_codecs_release_trybot',
@@ -1520,8 +1520,8 @@
       'release_bot', 'chrome_with_codecs',
     ],
 
-    'release_bot_enable_blink_heap_verification': [
-      'release_bot', 'enable_blink_heap_verification',
+    'release_bot_enable_blink_heap_verification_dcheck_always_on': [
+      'release_bot', 'enable_blink_heap_verification', 'dcheck_always_on',
     ],
 
     'release_bot_fuchsia': [