Support --dryRun in nanobench to get a list of benchmarks.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1681583002

Review URL: https://codereview.chromium.org/1681583002

1 files changed, 4 insertions, 1 deletions

diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 31efefa4f4..aeae4f41db 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -1082,10 +1082,13 @@ int nanobench_main() {
             SkCanvas* canvas = target->getCanvas();
             const char* config = target->config.name.c_str();
 
-            if (FLAGS_pre_log) {
+            if (FLAGS_pre_log || FLAGS_dryRun) {
                 SkDebugf("Running %s\t%s\n"
                          , bench->getUniqueName()
                          , config);
+                if (FLAGS_dryRun) {
+                    continue;
+                }
             }
 
             target->setup();