[wasm] Remove InitializeMemoryProtectionKeyForTesting

After https://crrev.com/c/3315446 we allocate the memory protection key
unconditionally, so the method is redundant.

R=ahaas@chromium.org

Bug: v8:11974
Change-Id: I205a0cda86dfaf394c68788a662241d76a3f8510
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3347562Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78412}

src/wasm/wasm-code-manager.cc

@@ -2127,12 +2127,6 @@ bool WasmCodeManager::MemoryProtectionKeyWritable() const {
   return wasm::MemoryProtectionKeyWritable(memory_protection_key_);
 }
 
-void WasmCodeManager::InitializeMemoryProtectionKeyForTesting() {
-  if (memory_protection_key_ == kNoMemoryProtectionKey) {
-    memory_protection_key_ = AllocateMemoryProtectionKey();
-  }
-}
-
 std::shared_ptr<NativeModule> WasmCodeManager::NewNativeModule(
     Isolate* isolate, const WasmFeatures& enabled, size_t code_size_estimate,
     std::shared_ptr<const WasmModule> module) {

src/wasm/wasm-code-manager.h

@@ -1058,10 +1058,6 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
   // Can only be called if {HasMemoryProtectionKeySupport()} is {true}.
   bool MemoryProtectionKeyWritable() const;
 
-  // This allocates a memory protection key (if none was allocated before),
-  // independent of the --wasm-memory-protection-keys flag.
-  void InitializeMemoryProtectionKeyForTesting();
-
  private:
   friend class WasmCodeAllocator;
   friend class WasmEngine;

test/unittests/wasm/memory-protection-unittest.cc

@@ -51,12 +51,9 @@ class MemoryProtectionTest : public TestWithNativeContext {
     mode_ = mode;
     bool enable_pku = mode == kPku || mode == kPkuWithMprotectFallback;
     FLAG_wasm_memory_protection_keys = enable_pku;
-    if (enable_pku) {
-      GetWasmCodeManager()->InitializeMemoryProtectionKeyForTesting();
-      // The key is initially write-protected.
-      CHECK_IMPLIES(GetWasmCodeManager()->HasMemoryProtectionKeySupport(),
-                    !GetWasmCodeManager()->MemoryProtectionKeyWritable());
-    }
+    // The key is initially write-protected.
+    CHECK_IMPLIES(GetWasmCodeManager()->HasMemoryProtectionKeySupport(),
+                  !GetWasmCodeManager()->MemoryProtectionKeyWritable());
 
     bool enable_mprotect =
         mode == kMprotect || mode == kPkuWithMprotectFallback;