Persist declarative rules to the extension state store.

chrome/browser/extensions/api/web_request/web_request_api.cc

Index: chrome/browser/extensions/api/web_request/web_request_api.cc
diff --git a/chrome/browser/extensions/api/web_request/web_request_api.cc b/chrome/browser/extensions/api/web_request/web_request_api.cc
index 04a4d698a62e3cb7fd9daefa08fff390071a7f4d..c6c4a46d7e86c5e40a3f8f72f8875358c8e53ed9 100644
--- a/chrome/browser/extensions/api/web_request/web_request_api.cc
+++ b/chrome/browser/extensions/api/web_request/web_request_api.cc
@@ -489,7 +489,8 @@ int ExtensionWebRequestEventRouter::OnBeforeRequest(
   bool initialize_blocked_requests = false;
 
   initialize_blocked_requests |=
-      ProcessDeclarativeRules(request, extensions::ON_BEFORE_REQUEST, NULL);
+      ProcessDeclarativeRules(profile, keys::kOnBeforeRequest, request,
+                              extensions::ON_BEFORE_REQUEST, NULL);
 
   int extra_info_spec = 0;
   std::vector<const EventListener*> listeners =
@@ -537,8 +538,8 @@ int ExtensionWebRequestEventRouter::OnBeforeSendHeaders(
   bool initialize_blocked_requests = false;
 
   initialize_blocked_requests |=
-      ProcessDeclarativeRules(request, extensions::ON_BEFORE_SEND_HEADERS,
-                              NULL);
+      ProcessDeclarativeRules(profile, keys::kOnBeforeSendHeaders, request,
+                              extensions::ON_BEFORE_SEND_HEADERS, NULL);
 
   int extra_info_spec = 0;
   std::vector<const EventListener*> listeners =
@@ -621,7 +622,8 @@ int ExtensionWebRequestEventRouter::OnHeadersReceived(
   bool initialize_blocked_requests = false;
 
   initialize_blocked_requests |=
-      ProcessDeclarativeRules(request, extensions::ON_HEADERS_RECEIVED,
+      ProcessDeclarativeRules(profile, keys::kOnHeadersReceived, request,
+                              extensions::ON_HEADERS_RECEIVED,
                               original_response_headers);
 
   int extra_info_spec = 0;
@@ -1269,8 +1271,9 @@ void ExtensionWebRequestEventRouter::DecrementBlockCount(
 
   base::TimeDelta block_time =
       base::Time::Now() - blocked_request.blocking_time;
-  request_time_tracker_->IncrementExtensionBlockTime(
-      extension_id, request_id, block_time);
+  if (!extension_id.empty())
+    request_time_tracker_->IncrementExtensionBlockTime(
+        extension_id, request_id, block_time);

[battre, 2012/06/15 22:56:49]

should we add a UMA statistic to measure the network delays at browser start
here? I am not sure how much this would tell us though as everything is slow
during browser startup. So if the UMA statistic tells us 10s, we don't know
whether the request had be answered instantly, if there was no need to load
declarative webrequest rules.

[Matt Perry, 2012/06/18 21:01:01]

Done.

 
   if (num_handlers_blocking == 0) {
     ExecuteDeltas(profile, request_id, true);
@@ -1399,12 +1402,26 @@ int ExtensionWebRequestEventRouter::ExecuteDeltas(
 }
 
 bool ExtensionWebRequestEventRouter::ProcessDeclarativeRules(
+    void* profile,
+    const std::string& event_name,
     net::URLRequest* request,
     extensions::RequestStages request_stage,
     net::HttpResponseHeaders* original_response_headers) {
   if (!rules_registry_.get())
     return false;
 
+  if (!rules_registry_->IsReady()) {

[battre, 2012/06/15 22:56:49]

nice! the architecture is really flexible.

[Matt Perry, 2012/06/18 21:01:01]

Agreed, I was pleasantly surprised with how simple this was to hook up. Great
job with the rules API and and webRequest hooks!

+    // The rules registry is still loading. Block this request until it
+    // finishes.
+    EventResponse* response = NULL;
+    rules_registry_->AddReadyCallback(
+        base::Bind(&ExtensionWebRequestEventRouter::DecrementBlockCount,
+                   AsWeakPtr(), profile, std::string(), event_name,
+                   request->identifier(), response));
+    blocked_requests_[request->identifier()].num_handlers_blocking++;

[Matt Perry, 2012/06/18 21:01:01]

BTW I had to add more initialization of blocked_requests_ here to mimic what
DispatchEvent does.

+    return true;
+  }
+
   base::Time start = base::Time::Now();
 
   // TODO(battre): Annotate deltas with extension IDs, so that we can