Milo: Grpc endpoint for multiple builds on a builder

milo/api/proto/buildbot.proto

Index: milo/api/proto/buildbot.proto
diff --git a/milo/api/proto/buildbot.proto b/milo/api/proto/buildbot.proto
index e8a038fa2f83dacb33398ae2c25a7cb0cd4c8021..07c276f1f4376c3252c7adece55ab6acc33215c4 100644
--- a/milo/api/proto/buildbot.proto
+++ b/milo/api/proto/buildbot.proto
@@ -12,6 +12,7 @@ import "google/protobuf/timestamp.proto";
 service Buildbot {
   rpc GetCompressedMasterJSON(MasterRequest) returns (CompressedMasterJSON) {}
   rpc GetBuildbotBuildJSON(BuildbotBuildRequest) returns (BuildbotBuildJSON) {}
+  rpc GetBuildbotBuildsJSON(BuildbotBuildsRequest) returns (BuildbotBuildsJSON) {}
 }
 
 // The request containing the name of the master.
@@ -43,3 +44,18 @@ message BuildbotBuildJSON {
   // Json data of the build.
   bytes data = 1;
 }
+
+// The request for multiple build on a builder.
+message BuildbotBuildsRequest {
+  string master = 1;
+  string builder = 2;
+  // Limit to the number of builds to return (default: 20).
+  int32 limit = 3;
+  // Include ongoing builds (default: false).
+  bool include_current = 4;
+}
+
+// The response message for multiple builds in a builder.
+message BuildbotBuildsJSON {
+  repeated BuildbotBuildJSON builds = 1;
+}