[benchmarking] update estimate for dawn_perf_tests

The current estimate of dawn_perf_tests is inaccurate. Updating the value based on actual runtime.

Bug: chromium:1130157
Change-Id: I5f2e4b22ae983d897062a7940e00250b15db743d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2472465Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Wenbin Zhang <wenbinzhang@google.com>
Cr-Commit-Position: refs/heads/master@{#817325}

tools/perf/core/bot_platforms.py

@@ -333,7 +333,7 @@ _MAC_HIGH_END_BENCHMARK_CONFIGS = PerfSuite(OFFICIAL_BENCHMARK_CONFIGS).Remove([
 ])
 _MAC_HIGH_END_EXECUTABLE_CONFIGS = frozenset([
     _base_perftests(),
-    _dawn_perf_tests(),
+    _dawn_perf_tests(330),
     _media_perftests(),
     _net_perftests(),
     _performance_browser_tests(),
@@ -359,7 +359,7 @@ _WIN_10_EXECUTABLE_CONFIGS = frozenset([
     _angle_perftests(),
     _base_perftests(),
     _components_perftests(),
-    _dawn_perf_tests(),
+    _dawn_perf_tests(600),
     _media_perftests(),
     _views_perftests(),
 ])