Ensure 'raises' clauses on operations are saved in IDL database.

client/dom/scripts/dartgenerator.py

Index: client/dom/scripts/dartgenerator.py
diff --git a/client/dom/scripts/dartgenerator.py b/client/dom/scripts/dartgenerator.py
index acff25a3a3adfcb94f860b2b7ed5d5664169e9d6..813443a2a9b620a15fb25b29b0049fd91730fc85 100755
--- a/client/dom/scripts/dartgenerator.py
+++ b/client/dom/scripts/dartgenerator.py
@@ -449,6 +449,10 @@ class DartGenerator(object):
         continue
       interfaces.append(interface)
 
+    # TODO(sra): Use this list of exception names to generate information to
+    # tell Frog which exceptions can be passed from JS to Dart code.
+    exceptions = self._CollectExceptions(interfaces)
+
     # Render all interfaces into Dart and save them in files.
     for interface in self._PreOrderInterfaces(interfaces):
 
@@ -630,6 +634,21 @@ class DartGenerator(object):
     return result;
 
 
+  def _CollectExceptions(self, interfaces):
+    """Returns the names of all exception classes raised."""
+    exceptions = set()
+    for interface in interfaces:
+      for attribute in interface.attributes:
+        if attribute.get_raises:
+          exceptions.add(attribute.get_raises.id)
+        if attribute.set_raises:
+          exceptions.add(attribute.set_raises.id)
+      for operation in interface.operations:
+        if operation.raises:
+          exceptions.add(operation.raises.id)
+    return exceptions
+
+
   def Flush(self):
     """Write out all pending files."""
     _logger.info('Flush...')