Refactoring: de-couple Extensions from "script injection System" [render side] : 1

extensions/browser/guest_view/web_view/web_view_guest.cc

Index: extensions/browser/guest_view/web_view/web_view_guest.cc
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.cc b/extensions/browser/guest_view/web_view/web_view_guest.cc
index 717770fe44d40121aa73d60011e47262f7f34473..da931f8db305aebd9e59b2ca5d52036ca4f9650c 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.cc
+++ b/extensions/browser/guest_view/web_view/web_view_guest.cc
@@ -59,6 +59,8 @@ namespace extensions {
 
 namespace {
 
+int current_script_injection_instance_id = 0;
+
 std::string WindowOpenDispositionToString(
   WindowOpenDisposition window_open_disposition) {
   switch (window_open_disposition) {
@@ -100,6 +102,10 @@ static std::string TerminationStatusToString(base::TerminationStatus status) {
   return "unknown";
 }
 
+int GetNextScriptInjectionInstanceID() {
+  return ++current_script_injection_instance_id;
+}
+
 std::string GetStoragePartitionIdFromSiteURL(const GURL& site_url) {
   const std::string& partition_id = site_url.query();
   bool persist_storage = site_url.path().find("persist") != std::string::npos;
@@ -185,6 +191,8 @@ using WebViewKey = std::pair<int, int>;
 using WebViewKeyToIDMap = std::map<WebViewKey, int>;
 static base::LazyInstance<WebViewKeyToIDMap> web_view_key_to_id_map =
     LAZY_INSTANCE_INITIALIZER;
+static base::LazyInstance<WebViewKeyToIDMap> script_injection_instance_id_map =
+     LAZY_INSTANCE_INITIALIZER;
 
 // static
 int WebViewGuest::GetOrGenerateRulesRegistryID(
@@ -208,6 +216,25 @@ int WebViewGuest::GetOrGenerateRulesRegistryID(
 }
 
 // static
+int WebViewGuest:: GetOrGenerateScriptInjectionInstanceID(
+    int embedder_process_id,
+    int guest_instance_id ) {
+  if (!(embedder_process_id && guest_instance_id))
+    return Host::kDefaultInstanceId;
+
+  WebViewKey key = std::make_pair(embedder_process_id, guest_instance_id);
+  WebViewKeyToIDMap& script_injection_ids =
+      script_injection_instance_id_map.Get();
+  auto it = script_injection_ids.find(key);
+  if (it != script_injection_ids.end())
+    return it->second;
+
+  int script_injection_instance_id = GetNextScriptInjectionInstanceID();
+  script_injection_ids[key] = script_injection_instance_id;
+  return script_injection_instance_id;
+}
+
+// static
 int WebViewGuest::GetViewInstanceId(WebContents* contents) {
   auto guest = FromWebContents(contents);
   if (!guest)
@@ -294,6 +321,10 @@ void WebViewGuest::DidInitialize(const base::DictionaryValue& create_params) {
       owner_web_contents()->GetRenderProcessHost()->GetID(),
       view_instance_id());
 
+  GetOrGenerateScriptInjectionInstanceID(
+      owner_web_contents()->GetRenderProcessHost()->GetID(),
+      guest_instance_id());
+
   // We must install the mapping from guests to WebViews prior to resuming
   // suspended resource loads so that the WebRequest API will catch resource
   // requests.
@@ -321,6 +352,7 @@ void WebViewGuest::EmbedderWillBeDestroyed() {
   WebViewKey key(owner_web_contents()->GetRenderProcessHost()->GetID(),
                  view_instance_id());
   web_view_key_to_id_map.Get().erase(key);
+  script_injection_instance_id_map.Get().erase(key);
 
   content::BrowserThread::PostTask(
       content::BrowserThread::IO,