[tools] Implement confidence-based number of runs

R=machenbach@chromium.org, tmrts@chromium.org

Bug: chromium:880724
Change-Id: I2b8ede244fa09868eef384b967223a3788ddd2a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1581180
Commit-Queue: Sergiy Belozorov <sergiyb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61370}

.vpython

@@ -66,3 +66,11 @@ wheel: <
   name: "infra/python/wheels/mock-py2_py3"
   version: "version:2.0.0"
 >
+
+# Used by:
+#   tools/run_perf.py
+#   tools/unittests/run_perf_test.py
+wheel: <
+  name: "infra/python/wheels/numpy/${vpython_platform}"
+  version: "version:1.11.3"
+>

BUILD.gn

@@ -3875,6 +3875,12 @@ group("gn_all") {
   }
 }
 
+group("v8_python_base") {
+  data = [
+    ".vpython",
+  ]
+}
+
 group("v8_clusterfuzz") {
   testonly = true
 

test/BUILD.gn

@@ -44,6 +44,7 @@ group("v8_perf") {
   testonly = true
 
   data_deps = [
+    "..:v8_python_base",
     "cctest:cctest",
     "..:d8",
     "../tools:v8_android_test_runner_deps",

tools/BUILD.gn

@@ -43,6 +43,7 @@ group("v8_testrunner") {
   testonly = true
 
   data_deps = [
+    "..:v8_python_base",
     "..:v8_dump_build_config",
     ":v8_android_test_runner_deps",
   ]