DL: Speculative fix for a leak in display_lock_fuzzer.

This replaces a leaky new with a local static variable for the display
lock fuzzer environment.

This is a speculative fix for the referenced bug.

R=schenney@chromium.org

Bug: 1013486
Change-Id: I717437eac8d3d6f3d81515e2822209a676047698
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873916
Commit-Queue: vmpstr <vmpstr@chromium.org>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709212}

third_party/blink/renderer/core/display_lock/display_lock_fuzzer.cc

@@ -9,23 +9,14 @@
 #include "third_party/blink/public/web/web_view.h"
 #include "third_party/blink/public/web/web_widget.h"
 
-static content::Env* env;
-
-bool Initialize() {
-  blink::WebRuntimeFeatures::EnableDisplayLocking(true);
-  env = new content::Env();
-  return true;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  static bool initialized = Initialize();
-  // Suppress unused variable warning.
-  (void)initialized;
-
   // Only handle reasonable size inputs.
   if (size < 1 || size > 10000)
     return 0;
 
+  blink::WebRuntimeFeatures::EnableDisplayLocking(true);
+  static base::NoDestructor<content::Env> env;
+
   std::string data_as_string(reinterpret_cast<const char*>(data), size);
   int num_rafs = std::hash<std::string>()(data_as_string) % 10;
   env->adapter->LoadHTML(data_as_string, "");