[Android] Java Bridge with Gin: implement Java Bridge dispatcher

content/common/gin_java_bridge_messages.h

Index: content/common/gin_java_bridge_messages.h
diff --git a/content/common/gin_java_bridge_messages.h b/content/common/gin_java_bridge_messages.h
index f9525b1e5a5c4ba11301855f47456977a1053ad0..51ec0a696c9c9e288a798309c230da614315e194 100644
--- a/content/common/gin_java_bridge_messages.h
+++ b/content/common/gin_java_bridge_messages.h
@@ -45,14 +45,15 @@ IPC_SYNC_MESSAGE_ROUTED2_1(GinJavaBridgeHostMsg_HasMethod,
 // a container to work around immutability of base::Value.
 // Empty result list indicates that an error has happened on the Java side
 // (either bridge-induced error or an unhandled Java exception) and an exception
-// must be thrown into JavaScript.
+// must be thrown into JavaScript with the text from |error_message|.
 // Some special value types that are not supported by base::Value are encoded
 // as BinaryValues via GinJavaBridgeValue.
-IPC_SYNC_MESSAGE_ROUTED3_1(GinJavaBridgeHostMsg_InvokeMethod,
+IPC_SYNC_MESSAGE_ROUTED3_2(GinJavaBridgeHostMsg_InvokeMethod,
                            int32 /* object_id */,
                            std::string /* method_name */,
                            base::ListValue /* arguments */,
-                           base::ListValue /* result */)
+                           base::ListValue /* result */,
+                           std::string /* error_message */)

[palmer, 2014/06/25 22:22:33]

It's generally better to send an error number/enum and then have the receiver
map it to a string. How large is the range of possible errors?

[mnaganov (inactive), 2014/06/26 13:41:35]

That's a really nice idea, thanks! Converting to use error codes has helped me
to reveal that one of the unit tests was testing a wrong thing.

 
 // Sent from renderer to browser in two cases:
 //