Re-land 125247: Better error messages when using unsupported manifest features.

chrome/common/extensions/manifest.cc

Index: chrome/common/extensions/manifest.cc
diff --git a/chrome/common/extensions/manifest.cc b/chrome/common/extensions/manifest.cc
index d462bb85bd9d48860fc3953f2e100a9ddc9390cc..0cf2ef275985c66ad0ef040cd2ceed232fd5dcc5 100644
--- a/chrome/common/extensions/manifest.cc
+++ b/chrome/common/extensions/manifest.cc
@@ -28,18 +28,24 @@ Manifest::~Manifest() {
 bool Manifest::ValidateManifest(string16* error) const {
   for (DictionaryValue::key_iterator key = value_->begin_keys();
        key != value_->end_keys(); ++key) {
-    bool was_known = false;
-    if (!CanAccessKey(*key, &was_known)) {
+    scoped_ptr<Feature> feature =
+        ManifestFeatureProvider::GetDefaultInstance()->GetFeature(*key);
+    if (!feature.get()) {
       // When validating the extension manifests, we ignore keys that are not
       // recognized for forward compatibility.
-      if (!was_known) {
-        // TODO(aa): Consider having an error here in the case of strict error
-        // checking to let developers know when they screw up.
-        continue;
-      }
+      // TODO(aa): Consider having an error here in the case of strict error
+      // checking to let developers know when they screw up.
+      continue;
+    }
 
+    Feature::Availability result = feature->IsAvailable(
+        extension_id_, GetType(), Feature::ConvertLocation(location_),
+        GetManifestVersion());
+    if (result != Feature::IS_AVAILABLE) {
       *error = ExtensionErrorUtils::FormatErrorMessageUTF16(
-          errors::kFeatureNotAllowed, *key);
+          errors::kFeatureNotAllowed,
+          *key,
+          feature->GetErrorMessage(result));
       return false;
     }
   }
@@ -48,7 +54,7 @@ bool Manifest::ValidateManifest(string16* error) const {
 }
 
 bool Manifest::HasKey(const std::string& key) const {
-  return CanAccessKey(key, NULL) && value_->HasKey(key);
+  return CanAccessKey(key) && value_->HasKey(key);
 }
 
 bool Manifest::Get(
@@ -140,22 +146,18 @@ bool Manifest::IsHostedApp() const {
 bool Manifest::CanAccessPath(const std::string& path) const {
   std::vector<std::string> components;
   base::SplitString(path, '.', &components);
-  return CanAccessKey(components[0], NULL);
+  return CanAccessKey(components[0]);
 }
 
-bool Manifest::CanAccessKey(const std::string& key, bool *was_known) const {
+bool Manifest::CanAccessKey(const std::string& key) const {
   scoped_ptr<Feature> feature =
       ManifestFeatureProvider::GetDefaultInstance()->GetFeature(key);
   if (!feature.get())
     return false;
 
-  if (was_known)
-    *was_known = true;
-
-  return feature->IsAvailable(extension_id_,
-                              GetType(),
-                              Feature::ConvertLocation(location_),
-                              GetManifestVersion());
+  return Feature::IS_AVAILABLE == feature->IsAvailable(
+      extension_id_, GetType(), Feature::ConvertLocation(location_),
+      GetManifestVersion());
 }
 
 }  // namespace extensions