Revert "Enable ServiceWorkerScriptFullCodeCache by default"

This reverts commit c4334bc5.

Reason for revert: Caused crashes when storing javascript modules in cache storage. https://crbug.com/832202

Original change's description:
> Enable ServiceWorkerScriptFullCodeCache by default
> 
> Bug: 768705,788619
> Change-Id: I18474261a0bb443b5ed7186adb8bc68227ece26c
> Reviewed-on: https://chromium-review.googlesource.com/994492
> Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#547946}

TBR=horo@chromium.org,kinuko@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 768705, 788619, 832202
Change-Id: I53d3a401dfb83fbf54184588ca889b1a4f9f0474
Reviewed-on: https://chromium-review.googlesource.com/1014310Reviewed-by: Tsuyoshi Horo <horo@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551258}

content/browser/service_worker/service_worker_browsertest.cc

@@ -2624,10 +2624,6 @@ class ServiceWorkerVersionBrowserV8CacheTest
       public ServiceWorkerVersion::Listener {
  public:
   using self = ServiceWorkerVersionBrowserV8CacheTest;
-  ServiceWorkerVersionBrowserV8CacheTest() {
-    scoped_feature_list_.InitAndDisableFeature(
-        features::kServiceWorkerScriptFullCodeCache);
-  }
   ~ServiceWorkerVersionBrowserV8CacheTest() override {
     if (version_)
       version_->RemoveListener(this);
@@ -2651,9 +2647,6 @@ class ServiceWorkerVersionBrowserV8CacheTest
 
   base::Closure cache_updated_closure_;
   size_t metadata_size_ = 0;
-
- private:
-  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 IN_PROC_BROWSER_TEST_F(ServiceWorkerVersionBrowserV8CacheTest, Restart) {

content/public/common/content_features.cc

@@ -342,7 +342,7 @@ const base::Feature kServiceWorkerPaymentApps{
 
 // Generate V8 full code cache of service worker scripts.
 const base::Feature kServiceWorkerScriptFullCodeCache{
-    "ServiceWorkerScriptFullCodeCache", base::FEATURE_ENABLED_BY_DEFAULT};
+    "ServiceWorkerScriptFullCodeCache", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Establish direct connection from clients to the service worker.
 const base::Feature kServiceWorkerServicification{