[code-cache] Log resources with no cache handler

Add another entry to the NoCacheReason enum, reporting that the chromium
ScriptResource has no cache handler.

Also, the amount of chromium-specific entries in this enum is getting
too high. So, added a TODO for removing them -- possibly in the future
we want to do this no-cache reason logging in Chromium after all,
propagating isolate cache hits and consume failures back up the API with
an out parameter.

Bug: chromium:769203
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I63ca863cfef61e04e7104318eb79810796b61a9c
Reviewed-on: https://chromium-review.googlesource.com/776893Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49458}

include/v8.h

@@ -1456,7 +1456,8 @@ class V8_EXPORT ScriptCompiler {
     kNoCacheBecauseV8Extension,
     kNoCacheBecauseExtensionModule,
     kNoCacheBecausePacScript,
-    kNoCacheBecauseInDocumentWrite
+    kNoCacheBecauseInDocumentWrite,
+    kNoCacheBecauseResourceWithNoCacheHandler
   };
 
   /**

src/compiler.cc

@@ -1236,6 +1236,9 @@ namespace {
 
 struct ScriptCompileTimerScope {
  public:
+  // TODO(leszeks): There are too many blink-specific entries in this enum,
+  // figure out a way to push produce/hit-isolate-cache/consume/consume-failed
+  // back up the API and log them in blink instead.
   enum class CacheBehaviour {
     kProduceCodeCache,
     kHitIsolateCacheWhenNoCache,
@@ -1256,6 +1259,7 @@ struct ScriptCompileTimerScope {
     kNoCacheBecauseExtensionModule,
     kNoCacheBecausePacScript,
     kNoCacheBecauseInDocumentWrite,
+    kNoCacheBecauseResourceWithNoCacheHandler,
     kCount
   };
 
@@ -1360,6 +1364,8 @@ struct ScriptCompileTimerScope {
         return CacheBehaviour::kNoCacheBecausePacScript;
       case ScriptCompiler::kNoCacheBecauseInDocumentWrite:
         return CacheBehaviour::kNoCacheBecauseInDocumentWrite;
+      case ScriptCompiler::kNoCacheBecauseResourceWithNoCacheHandler:
+        return CacheBehaviour::kNoCacheBecauseResourceWithNoCacheHandler;
     }
     UNREACHABLE();
   }
@@ -1406,6 +1412,7 @@ struct ScriptCompileTimerScope {
       case CacheBehaviour::kNoCacheBecauseExtensionModule:
       case CacheBehaviour::kNoCacheBecausePacScript:
       case CacheBehaviour::kNoCacheBecauseInDocumentWrite:
+      case CacheBehaviour::kNoCacheBecauseResourceWithNoCacheHandler:
         return isolate_->counters()->compile_script_no_cache_other();
 
       case CacheBehaviour::kCount:

src/counters.h

@@ -1066,7 +1066,7 @@ class RuntimeCallTimerScope {
      20)                                                                       \
   HR(wasm_lazy_compilation_throughput, V8.WasmLazyCompilationThroughput, 1,    \
      10000, 50)                                                                \
-  HR(compile_script_cache_behaviour, V8.CompileScript.CacheBehaviour, 0, 18, 19)
+  HR(compile_script_cache_behaviour, V8.CompileScript.CacheBehaviour, 0, 19, 20)
 
 #define HISTOGRAM_TIMER_LIST(HT)                                               \
   /* Garbage collection timers. */                                             \