diff --git a/DEPS b/DEPS
index f30b473..dc32bcf 100644
--- a/DEPS
+++ b/DEPS
@@ -174,7 +174,7 @@
   "webdev_rev": "832b096c0c24798d3df46faa7b7661fe930573c2",
   "webkit_inspection_protocol_rev": "dd6fb5d8b536e19cedb384d0bbf1f5631923f1e8",
   "yaml_edit_rev": "df1452bfe1653286277a1a8f34dddf3e4fbedd9e",
-  "yaml_rev": "2af44871f684c89e973a96e39026b8b88dda1987",
+  "yaml_rev": "ad0779d1baa25c6b10a192d080efc45de02b6a32",
   "zlib_rev": "bf44340d1b6be1af8950bbdf664fec0cf5a831cc",
   "crashpad_rev": "bf327d8ceb6a669607b0dbab5a83a275d03f99ed",
   "minichromium_rev": "8d641e30a8b12088649606b912c2bc4947419ccc",
diff --git a/tests/language/constants_2018/constant_types_test.dart b/tests/language/constants_2018/constant_types_test.dart
index 2c8dee1..44a4d5f 100644
--- a/tests/language/constants_2018/constant_types_test.dart
+++ b/tests/language/constants_2018/constant_types_test.dart
@@ -4,7 +4,7 @@
 
 // Tests that in some positions only constant types are allowed, so not
 // type parameters. But in other positions potentially constant types are
-// allowed, so type parameters.
+// allowed, including type parameters.
 
 import "package:expect/expect.dart";
 
@@ -24,7 +24,7 @@
   ;
   const T.test4()
       : value = null //
-            ?? X //# 04: compile-time error
+            ?? X //# 04: ok
   ;
 }
 
diff --git a/tools/VERSION b/tools/VERSION
index 1cb0e87..bc7478b 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 15
 PATCH 0
-PRERELEASE 156
+PRERELEASE 157
 PRERELEASE_PATCH 0
\ No newline at end of file
diff --git a/tools/bots/test_matrix.json b/tools/bots/test_matrix.json
index 20a574e..50dc881 100644
--- a/tools/bots/test_matrix.json
+++ b/tools/bots/test_matrix.json
@@ -412,6 +412,17 @@
         "use-sdk": true
       }
     },
+    "web-unittest-asserts-(linux|mac|win)": {
+      "options": {
+        "builder-tag": "web",
+        "compiler": "dartk",
+        "enable-asserts": true,
+        "mode": "release",
+        "runtime": "vm",
+        "timeout": 240,
+        "use-sdk": true
+      }
+    },
     "unittest-asserts-(debug|product|release)-(linux|mac|win)": {
       "options": {
         "compiler": "dartk",
@@ -421,15 +432,6 @@
         "use-sdk": true
       }
     },
-    "unittest-weak-asserts-no-sdk-(linux|mac|win)": {
-      "options": {
-        "compiler": "dartk",
-        "enable-asserts": true,
-        "mode": "release",
-        "runtime": "vm",
-        "timeout": 240
-      }
-    },
     "analyzer-unittest-asserts-(debug|product|release)-(linux|mac|win)": {
       "options": {
         "compiler": "dartk",
@@ -456,15 +458,6 @@
     "vm-ffi-unit-test": {
       "__comment__": "This configuration is only used for a custom test runner. If it conflicts with a new configuration you are adding, you can make this configuration more specific by adding options."
     },
-    "unittest-asserts-no-sdk-(linux|mac|win)": {
-      "options": {
-        "compiler": "dartk",
-        "enable-asserts": true,
-        "mode": "release",
-        "runtime": "vm",
-        "timeout": 240
-      }
-    },
     "unittest-analyzer_use_fasta-(linux|mac|win)": {
       "options": {
         "compiler": "none",
@@ -2457,7 +2450,7 @@
           "testRunner": true,
           "arguments": [
             "pkg/compiler/tool/modular_test_suite.dart",
-            "-nunittest-asserts-no-sdk-linux",
+            "-nweb-unittest-asserts-linux",
             "--verbose",
             "--use-sdk"
           ]
@@ -2465,16 +2458,18 @@
         {
           "name": "js_runtime unit tests",
           "arguments": [
-            "-nunittest-asserts-no-sdk-linux",
+            "-nweb-unittest-asserts-linux",
             "pkg//js_runtime/"
           ]
         },
         {
           "name": "dart2js unit tests",
           "arguments": [
-            "-nunittest-asserts-no-sdk-linux",
+            "-nweb-unittest-asserts-linux",
             "pkg//compiler/"
-          ]
+          ],
+          "shards": 3,
+          "fileset": "web_platform"
         }
       ]
     },