Revert of Signal extension API schema corruption to the browser process.

extensions/common/extension_api.cc

Index: extensions/common/extension_api.cc
diff --git a/extensions/common/extension_api.cc b/extensions/common/extension_api.cc
index 1e70cb7ed3b063feebfe55ed59e9de0d80d673b8..4b49a83f8e5f70492f0aee34901739c1b85f1ce7 100644
--- a/extensions/common/extension_api.cc
+++ b/extensions/common/extension_api.cc
@@ -55,24 +55,15 @@
       NULL,                                                   // error code
       &error_message));
 
-#if DCHECK_IS_ON()
-  // |schema| comes from JSON hard-coded to the Chrome binary, so in principle
-  // failure to parse indicates we generated corrupted JSON, but in practice
-  // corruption of the Chrome binary (e.g. disk errors) can also break it.
-  // See http://crbug.com/121424.
-  if (!result || !result->IsType(base::Value::TYPE_LIST)) {
-    char buf[128];
-    base::snprintf(buf, arraysize(buf), "%s: (%d) '%s'", name.c_str(),
-                   result.get() ? result->GetType() : -1,
-                   error_message.c_str());
-
-    DCHECK(result) << "JSON parse failed: " << buf;
-    DCHECK(result->IsType(base::Value::TYPE_LIST)) << "JSON wrong type: "
-                                                   << buf;
-  }
-#endif  // DCHECK_IS_ON()
-
-  // From() returns null if passed a null or non-list value.
+  // Tracking down http://crbug.com/121424
+  char buf[128];
+  base::snprintf(buf, arraysize(buf), "%s: (%d) '%s'",
+      name.c_str(),
+      result.get() ? result->GetType() : -1,
+      error_message.c_str());
+
+  CHECK(result.get()) << error_message << " for schema " << schema;
+  CHECK(result->IsType(base::Value::TYPE_LIST)) << " for schema " << schema;
   return base::ListValue::From(std::move(result));
 }
 
@@ -223,9 +214,6 @@
 void ExtensionAPI::LoadSchema(const std::string& name,
                               const base::StringPiece& schema) {
   std::unique_ptr<base::ListValue> schema_list(LoadSchemaList(name, schema));
-  if (!schema_list)
-    return;
-
   std::string schema_namespace;
   extensions::ExtensionsClient* extensions_client =
       extensions::ExtensionsClient::Get();
@@ -343,12 +331,7 @@
     }
 
     maybe_schema = schemas_.find(api_name);
-    // If the schema failed to load then return null for it, rather than
-    // crashing, so that the browser can be notified of the problem.
-    // See http://crbug.com/121424.
-    if (schemas_.end() == maybe_schema)
-      return NULL;
-
+    CHECK(schemas_.end() != maybe_schema);
     result = maybe_schema->second.get();
   }
 
@@ -407,9 +390,7 @@
     api_name_candidate = api_name_candidate.substr(0, last_dot_index);
   }
 
-  if (child_name)
-    *child_name = "";
-
+  *child_name = "";
   return std::string();
 }