Mojo: Log an error when we fail to find a JS module.

gin/modules/file_module_provider.cc

Index: gin/modules/file_module_provider.cc
diff --git a/gin/modules/file_module_provider.cc b/gin/modules/file_module_provider.cc
index 660d9b1b9ac2e2a1e60f56cc78827abc0975fce3..dfadf8e6a5a54c01eaeabb531fa1fa5d93de62c3 100644
--- a/gin/modules/file_module_provider.cc
+++ b/gin/modules/file_module_provider.cc
@@ -14,11 +14,14 @@ namespace gin {
 
 namespace {
 
-void AttempToLoadModule(const base::WeakPtr<Runner>& runner,
-                        const std::vector<base::FilePath>& search_paths,
-                        const std::string& id) {
-  if (!runner)
+void AttemptToLoadModule(const base::WeakPtr<Runner>& runner,
+                         const std::vector<base::FilePath>& search_paths,
+                         const std::string& id,
+                         base::Callback<void(bool)> callback) {
+  if (!runner) {
+    callback.Run(false);
     return;
+  }
 
   std::vector<std::string> components;
   base::SplitString(id, '/', &components);
@@ -38,21 +41,23 @@ void AttempToLoadModule(const base::WeakPtr<Runner>& runner,
 
     Runner::Scope scope(runner.get());
     runner->Run(source, id);
+    callback.Run(true);
     return;
   }
+  callback.Run(false);

[abarth-chromium, 2014/07/22 22:16:15]

Maybe we should just log something at this point and not wait for the system to
stop churning?  We should probably be looking on disk last anyway.

[Matt Perry, 2014/07/22 22:24:40]

Huh.. I thought I tried that and it resulted in false positives. But it seems to
work. That's way simpler. I'll do that.

 }
 
 }  // namespace
 
 FileModuleProvider::FileModuleProvider(
     const std::vector<base::FilePath>& search_paths)
-    : search_paths_(search_paths) {
+    : weak_factory_(this), search_paths_(search_paths) {
 }
 
 FileModuleProvider::~FileModuleProvider() {
 }
 
-void FileModuleProvider::AttempToLoadModules(
+void FileModuleProvider::AttemptToLoadModules(
     Runner* runner, const std::set<std::string>& ids) {
   std::set<std::string> modules = ids;
   for (std::set<std::string>::const_iterator it = modules.begin();
@@ -62,7 +67,22 @@ void FileModuleProvider::AttempToLoadModules(
       continue;
     attempted_ids_.insert(id);
     base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
-        AttempToLoadModule, runner->GetWeakPtr(), search_paths_, id));
+        AttemptToLoadModule, runner->GetWeakPtr(), search_paths_, id,
+        base::Bind(&FileModuleProvider::OnReadCompleted,
+                   weak_factory_.GetWeakPtr(), id)));
+  }
+}
+
+void FileModuleProvider::OnReadCompleted(const std::string& id, bool success) {
+  if (success) {
+    successful_ids_.insert(id);
+  } else {
+    failed_ids_.insert(id);
+  }
+
+  if (failed_ids_.size() + successful_ids_.size() == attempted_ids_.size()) {
+    if (!completion_callback_.is_null())
+      completion_callback_.Run(successful_ids_);
   }
 }