ArtProfileWriter to add classes of hot methods.

Summary:
https://www.internalfb.com/code/fbsource/[178198e42623]/fbandroid/native/baseline_profiles/manual_profile.py?lines=47-48
this line of code in the baseline profile generator makes it clear that in manual profile (which includes profile from redex), a class has to be its own line in order to be picked into baseline profile, and eventually hopefully in app image.
Remember, a method line starts with its flag like 'H', "S', 'P', never 'L'.

So this change makes sure class of any hot method (and also startup-only method that will be included into profile) is included into baseline profile.

Reviewed By: NTillmann

Differential Revision: D51322912

fbshipit-source-id: 679ef61fdf41f67fc2c1cfa063e71b07f2608edb

opt/art-profile-writer/ArtProfileWriterPass.cpp

@@ -112,11 +112,18 @@ void ArtProfileWriterPass::run_pass(DexStoresVector& stores,
   for (size_t dex_idx = 0; dex_idx < end; dex_idx++) {
     auto& dex = dexen.at(dex_idx);
     for (auto* cls : dex) {
+      bool should_include_class = false;
       for (auto* method : cls->get_all_methods()) {
         auto it = method_flags.find(method);
         if (it == method_flags.end()) {
           continue;
         }
+        // hot method's class should be included.
+        // In addition, if we include non-hot startup method, we also need to
+        // include its class.
+        if (it->second.hot || (it->second.startup && !it->second.not_startup)) {
+          should_include_class = true;
+        }
         std::string descriptor = show_deobfuscated(method);
         // reformat it into manual profile pattern so baseline profile generator
         // in post-process can recognize the method
@@ -125,6 +132,9 @@ void ArtProfileWriterPass::run_pass(DexStoresVector& stores,
         ofs << it->second << descriptor << std::endl;
         methods_with_baseline_profile++;
       }
+      if (should_include_class) {
+        ofs << show_deobfuscated(cls) << std::endl;
+      }
     }
   }