ServiceWorker: Migrate the script cache backend from BlockFile to Simple

content/browser/appcache/appcache_disk_cache.cc

Index: content/browser/appcache/appcache_disk_cache.cc
diff --git a/content/browser/appcache/appcache_disk_cache.cc b/content/browser/appcache/appcache_disk_cache.cc
index 03d348c76bba246197ddaddad410ffccb63caa49..8419e11c5104714d8aaf27cba225f197fafa21c9 100644
--- a/content/browser/appcache/appcache_disk_cache.cc
+++ b/content/browser/appcache/appcache_disk_cache.cc
@@ -260,7 +260,7 @@ int AppCacheDiskCache::CreateEntry(int64 key, Entry** entry,
   if (is_disabled_)
     return net::ERR_ABORTED;
 
-  if (is_initializing()) {
+  if (is_initializing_or_waiting_to_initialize()) {
     pending_calls_.push_back(PendingCall(CREATE, key, entry, callback));
     return net::ERR_IO_PENDING;
   }
@@ -279,7 +279,7 @@ int AppCacheDiskCache::OpenEntry(int64 key, Entry** entry,
   if (is_disabled_)
     return net::ERR_ABORTED;
 
-  if (is_initializing()) {
+  if (is_initializing_or_waiting_to_initialize()) {
     pending_calls_.push_back(PendingCall(OPEN, key, entry, callback));
     return net::ERR_IO_PENDING;
   }
@@ -297,7 +297,7 @@ int AppCacheDiskCache::DoomEntry(int64 key,
   if (is_disabled_)
     return net::ERR_ABORTED;
 
-  if (is_initializing()) {
+  if (is_initializing_or_waiting_to_initialize()) {
     pending_calls_.push_back(PendingCall(DOOM, key, NULL, callback));
     return net::ERR_IO_PENDING;
   }
@@ -311,6 +311,7 @@ int AppCacheDiskCache::DoomEntry(int64 key,
 AppCacheDiskCache::AppCacheDiskCache(bool use_simple_cache)
     : use_simple_cache_(use_simple_cache),
       is_disabled_(false),
+      is_waiting_to_initialize_(false),
       weak_factory_(this) {
 }
 
@@ -339,7 +340,7 @@ int AppCacheDiskCache::Init(
     bool force,
     const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread,
     const net::CompletionCallback& callback) {
-  DCHECK(!is_initializing() && !disk_cache_.get());
+  DCHECK(!is_initializing_or_waiting_to_initialize() && !disk_cache_.get());
   is_disabled_ = false;
   create_backend_callback_ = new CreateBackendCallbackShim(this);