[wasm] Remove redundant GetSharedWireBytesStorage

It does exactly the same as GetWireBytesStorage.
Also change the WasmCompilationUnit::ExecuteCompilation method to
receive a reference to the shared_ptr, since it does not take (shared)
ownership. This saves one ref count increment and decrement.

R=titzer@chromium.org

Bug: v8:8689
Change-Id: I03c3ec5f907c738c73e0dc16646d78ecac3f3717
Reviewed-on: https://chromium-review.googlesource.com/c/1417632
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58908}

src/wasm/function-compiler.cc

@@ -54,8 +54,8 @@ WasmCompilationUnit::~WasmCompilationUnit() = default;
 
 void WasmCompilationUnit::ExecuteCompilation(
     CompilationEnv* env, NativeModule* native_module,
-    std::shared_ptr<WireBytesStorage> wire_bytes_storage, Counters* counters,
-    WasmFeatures* detected) {
+    const std::shared_ptr<WireBytesStorage>& wire_bytes_storage,
+    Counters* counters, WasmFeatures* detected) {
   auto* func = &env->module->functions[func_index_];
   Vector<const uint8_t> code = wire_bytes_storage->GetCode(func->code);
   wasm::FunctionBody func_body{func->sig, func->code.offset(), code.start(),

src/wasm/function-compiler.h

@@ -42,7 +42,7 @@ class WasmCompilationUnit final {
   ~WasmCompilationUnit();
 
   void ExecuteCompilation(CompilationEnv*, NativeModule*,
-                          std::shared_ptr<WireBytesStorage>, Counters*,
+                          const std::shared_ptr<WireBytesStorage>&, Counters*,
                           WasmFeatures* detected);
 
   ExecutionTier tier() const { return tier_; }

src/wasm/module-compiler.cc

@@ -137,12 +137,6 @@ class CompilationStateImpl {
     return WasmError{error->error.offset(), error_msg.str()};
   }
 
-  std::shared_ptr<WireBytesStorage> GetSharedWireBytesStorage() const {
-    base::MutexGuard guard(&mutex_);
-    DCHECK_NOT_NULL(wire_bytes_storage_);
-    return wire_bytes_storage_;
-  }
-
   void SetWireBytesStorage(
       std::shared_ptr<WireBytesStorage> wire_bytes_storage) {
     base::MutexGuard guard(&mutex_);
@@ -151,6 +145,7 @@ class CompilationStateImpl {
 
   std::shared_ptr<WireBytesStorage> GetWireBytesStorage() const {
     base::MutexGuard guard(&mutex_);
+    DCHECK_NOT_NULL(wire_bytes_storage_);
     return wire_bytes_storage_;
   }
 
@@ -496,8 +491,8 @@ bool FetchAndExecuteCompilationUnit(CompilationEnv* env,
   // if baseline bails out.
   ExecutionTier tier = unit->tier();
   unit->ExecuteCompilation(env, native_module,
-                           compilation_state->GetSharedWireBytesStorage(),
-                           counters, detected);
+                           compilation_state->GetWireBytesStorage(), counters,
+                           detected);
   compilation_state->OnFinishedUnit(tier, unit->result());
 
   return true;