Increase decoder perftest iteration count.

The decoder microbenchmarks suffer from fairly high variance. This
should decrease the variance while not changing the absolute total.

Also add a mode for a fast test run on the bots with DCHECK enabled.
The test time on the perf bots should still be within one minute.

Bug: angleproject:2763
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Idf5fb0f4cb32205c8c640415b5e6ff22efa5b7b1
Reviewed-on: https://chromium-review.googlesource.com/c/1286753
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601261}

gpu/command_buffer/tests/decoder_perftest.cc

@@ -39,8 +39,8 @@
 namespace gpu {
 namespace {
 
-constexpr int kDefaultRuns = 4;
-constexpr int kDefaultIterations = 10000;
+constexpr int kDefaultRuns = 8;
+constexpr int kDefaultIterations = 50000;
 
 // A command buffer that can record and replay commands
 // This goes through 3 states, allowing setting up of initial state before
@@ -361,6 +361,10 @@ class PerfIterator {
     // 3- avoid unneeded syscalls (time, print).
     for_linux_perf_ =
         base::CommandLine::ForCurrentProcess()->HasSwitch("for-linux-perf");
+    if (base::CommandLine::ForCurrentProcess()->HasSwitch("fast-run")) {
+      runs_ = 1;
+      iterations_ = 100;
+    }
   }
 
   bool Iterate() {

testing/buildbot/chromium.gpu.fyi.json

@@ -13341,7 +13341,8 @@
         "args": [
           "-v",
           "--use-cmd-decoder=passthrough",
-          "--use-angle=gl-null"
+          "--use-angle=gl-null",
+          "--fast-run"
         ],
         "isolate_name": "command_buffer_perftests",
         "name": "passthrough_command_buffer_perftests",
@@ -13369,7 +13370,8 @@
         "args": [
           "-v",
           "--use-cmd-decoder=validating",
-          "--use-stub"
+          "--use-stub",
+          "--fast-run"
         ],
         "isolate_name": "command_buffer_perftests",
         "name": "validating_command_buffer_perftests",
@@ -16342,7 +16344,8 @@
         "args": [
           "-v",
           "--use-cmd-decoder=passthrough",
-          "--use-angle=gl-null"
+          "--use-angle=gl-null",
+          "--fast-run"
         ],
         "isolate_name": "command_buffer_perftests",
         "name": "passthrough_command_buffer_perftests",
@@ -16482,7 +16485,8 @@
         "args": [
           "-v",
           "--use-cmd-decoder=validating",
-          "--use-stub"
+          "--use-stub",
+          "--fast-run"
         ],
         "isolate_name": "command_buffer_perftests",
         "name": "validating_command_buffer_perftests",

testing/buildbot/test_suites.pyl

@@ -1250,6 +1250,7 @@
           '-v',
           '--use-cmd-decoder=passthrough',
           '--use-angle=gl-null',
+          '--fast-run',
         ],
       },
       # TODO(jmadill): Run on Linux bots when possible.
@@ -1259,6 +1260,7 @@
           '-v',
           '--use-cmd-decoder=validating',
           '--use-stub',
+          '--fast-run',
         ],
       },
     },