diff --git a/ui/metrics/metrics_proto/combined_metrics.pb.go b/ui/metrics/metrics_proto/combined_metrics.pb.go
new file mode 100644
index 0000000..f49d64d
--- /dev/null
+++ b/ui/metrics/metrics_proto/combined_metrics.pb.go
@@ -0,0 +1,239 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.33.0
+// 	protoc        v3.21.12
+// source: combined_metrics.proto
+
+package metrics_proto
+
+import (
+	find_input_delta_proto "android/soong/cmd/find_input_delta/find_input_delta_proto"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+// These field numbers are also found in the inner message declarations.
+// We verify that the values are the same, and that every enum value is checked
+// in combined_metrics_test.go.
+// Do not change this enum without also updating:
+//   - the submessage's .proto file
+//   - combined_metrics_test.go
+type FieldNumbers int32
+
+const (
+	FieldNumbers_FIELD_NUMBERS_UNSPECIFIED FieldNumbers = 0
+	FieldNumbers_FIELD_NUMBERS_FILE_LIST   FieldNumbers = 1
+)
+
+// Enum value maps for FieldNumbers.
+var (
+	FieldNumbers_name = map[int32]string{
+		0: "FIELD_NUMBERS_UNSPECIFIED",
+		1: "FIELD_NUMBERS_FILE_LIST",
+	}
+	FieldNumbers_value = map[string]int32{
+		"FIELD_NUMBERS_UNSPECIFIED": 0,
+		"FIELD_NUMBERS_FILE_LIST":   1,
+	}
+)
+
+func (x FieldNumbers) Enum() *FieldNumbers {
+	p := new(FieldNumbers)
+	*p = x
+	return p
+}
+
+func (x FieldNumbers) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (FieldNumbers) Descriptor() protoreflect.EnumDescriptor {
+	return file_combined_metrics_proto_enumTypes[0].Descriptor()
+}
+
+func (FieldNumbers) Type() protoreflect.EnumType {
+	return &file_combined_metrics_proto_enumTypes[0]
+}
+
+func (x FieldNumbers) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Do not use.
+func (x *FieldNumbers) UnmarshalJSON(b []byte) error {
+	num, err := protoimpl.X.UnmarshalJSONEnum(x.Descriptor(), b)
+	if err != nil {
+		return err
+	}
+	*x = FieldNumbers(num)
+	return nil
+}
+
+// Deprecated: Use FieldNumbers.Descriptor instead.
+func (FieldNumbers) EnumDescriptor() ([]byte, []int) {
+	return file_combined_metrics_proto_rawDescGZIP(), []int{0}
+}
+
+type SoongCombinedMetrics struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	// cmd/find_input_delta/find_input_delta_proto.FileList
+	FileList *find_input_delta_proto.FileList `protobuf:"bytes,1,opt,name=file_list,json=fileList" json:"file_list,omitempty"`
+}
+
+func (x *SoongCombinedMetrics) Reset() {
+	*x = SoongCombinedMetrics{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_combined_metrics_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *SoongCombinedMetrics) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*SoongCombinedMetrics) ProtoMessage() {}
+
+func (x *SoongCombinedMetrics) ProtoReflect() protoreflect.Message {
+	mi := &file_combined_metrics_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use SoongCombinedMetrics.ProtoReflect.Descriptor instead.
+func (*SoongCombinedMetrics) Descriptor() ([]byte, []int) {
+	return file_combined_metrics_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *SoongCombinedMetrics) GetFileList() *find_input_delta_proto.FileList {
+	if x != nil {
+		return x.FileList
+	}
+	return nil
+}
+
+var File_combined_metrics_proto protoreflect.FileDescriptor
+
+var file_combined_metrics_proto_rawDesc = []byte{
+	0x0a, 0x16, 0x63, 0x6f, 0x6d, 0x62, 0x69, 0x6e, 0x65, 0x64, 0x5f, 0x6d, 0x65, 0x74, 0x72, 0x69,
+	0x63, 0x73, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x13, 0x73, 0x6f, 0x6f, 0x6e, 0x67, 0x5f,
+	0x62, 0x75, 0x69, 0x6c, 0x64, 0x5f, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x1a, 0x3b, 0x63,
+	0x6d, 0x64, 0x2f, 0x66, 0x69, 0x6e, 0x64, 0x5f, 0x69, 0x6e, 0x70, 0x75, 0x74, 0x5f, 0x64, 0x65,
+	0x6c, 0x74, 0x61, 0x2f, 0x66, 0x69, 0x6e, 0x64, 0x5f, 0x69, 0x6e, 0x70, 0x75, 0x74, 0x5f, 0x64,
+	0x65, 0x6c, 0x74, 0x61, 0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x66, 0x69, 0x6c, 0x65, 0x5f,
+	0x6c, 0x69, 0x73, 0x74, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x22, 0x5d, 0x0a, 0x14, 0x53, 0x6f,
+	0x6f, 0x6e, 0x67, 0x43, 0x6f, 0x6d, 0x62, 0x69, 0x6e, 0x65, 0x64, 0x4d, 0x65, 0x74, 0x72, 0x69,
+	0x63, 0x73, 0x12, 0x45, 0x0a, 0x09, 0x66, 0x69, 0x6c, 0x65, 0x5f, 0x6c, 0x69, 0x73, 0x74, 0x18,
+	0x01, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x28, 0x2e, 0x61, 0x6e, 0x64, 0x72, 0x6f, 0x69, 0x64, 0x2e,
+	0x66, 0x69, 0x6e, 0x64, 0x5f, 0x69, 0x6e, 0x70, 0x75, 0x74, 0x5f, 0x64, 0x65, 0x6c, 0x74, 0x61,
+	0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2e, 0x46, 0x69, 0x6c, 0x65, 0x4c, 0x69, 0x73, 0x74, 0x52,
+	0x08, 0x66, 0x69, 0x6c, 0x65, 0x4c, 0x69, 0x73, 0x74, 0x2a, 0x4a, 0x0a, 0x0c, 0x46, 0x69, 0x65,
+	0x6c, 0x64, 0x4e, 0x75, 0x6d, 0x62, 0x65, 0x72, 0x73, 0x12, 0x1d, 0x0a, 0x19, 0x46, 0x49, 0x45,
+	0x4c, 0x44, 0x5f, 0x4e, 0x55, 0x4d, 0x42, 0x45, 0x52, 0x53, 0x5f, 0x55, 0x4e, 0x53, 0x50, 0x45,
+	0x43, 0x49, 0x46, 0x49, 0x45, 0x44, 0x10, 0x00, 0x12, 0x1b, 0x0a, 0x17, 0x46, 0x49, 0x45, 0x4c,
+	0x44, 0x5f, 0x4e, 0x55, 0x4d, 0x42, 0x45, 0x52, 0x53, 0x5f, 0x46, 0x49, 0x4c, 0x45, 0x5f, 0x4c,
+	0x49, 0x53, 0x54, 0x10, 0x01, 0x42, 0x28, 0x5a, 0x26, 0x61, 0x6e, 0x64, 0x72, 0x6f, 0x69, 0x64,
+	0x2f, 0x73, 0x6f, 0x6f, 0x6e, 0x67, 0x2f, 0x75, 0x69, 0x2f, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63,
+	0x73, 0x2f, 0x6d, 0x65, 0x74, 0x72, 0x69, 0x63, 0x73, 0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f,
+}
+
+var (
+	file_combined_metrics_proto_rawDescOnce sync.Once
+	file_combined_metrics_proto_rawDescData = file_combined_metrics_proto_rawDesc
+)
+
+func file_combined_metrics_proto_rawDescGZIP() []byte {
+	file_combined_metrics_proto_rawDescOnce.Do(func() {
+		file_combined_metrics_proto_rawDescData = protoimpl.X.CompressGZIP(file_combined_metrics_proto_rawDescData)
+	})
+	return file_combined_metrics_proto_rawDescData
+}
+
+var file_combined_metrics_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
+var file_combined_metrics_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
+var file_combined_metrics_proto_goTypes = []interface{}{
+	(FieldNumbers)(0),                       // 0: soong_build_metrics.FieldNumbers
+	(*SoongCombinedMetrics)(nil),            // 1: soong_build_metrics.SoongCombinedMetrics
+	(*find_input_delta_proto.FileList)(nil), // 2: android.find_input_delta_proto.FileList
+}
+var file_combined_metrics_proto_depIdxs = []int32{
+	2, // 0: soong_build_metrics.SoongCombinedMetrics.file_list:type_name -> android.find_input_delta_proto.FileList
+	1, // [1:1] is the sub-list for method output_type
+	1, // [1:1] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_combined_metrics_proto_init() }
+func file_combined_metrics_proto_init() {
+	if File_combined_metrics_proto != nil {
+		return
+	}
+	if !protoimpl.UnsafeEnabled {
+		file_combined_metrics_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*SoongCombinedMetrics); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_combined_metrics_proto_rawDesc,
+			NumEnums:      1,
+			NumMessages:   1,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_combined_metrics_proto_goTypes,
+		DependencyIndexes: file_combined_metrics_proto_depIdxs,
+		EnumInfos:         file_combined_metrics_proto_enumTypes,
+		MessageInfos:      file_combined_metrics_proto_msgTypes,
+	}.Build()
+	File_combined_metrics_proto = out.File
+	file_combined_metrics_proto_rawDesc = nil
+	file_combined_metrics_proto_goTypes = nil
+	file_combined_metrics_proto_depIdxs = nil
+}
diff --git a/ui/metrics/metrics_proto/combined_metrics.proto b/ui/metrics/metrics_proto/combined_metrics.proto
new file mode 100644
index 0000000..3cd9a53
--- /dev/null
+++ b/ui/metrics/metrics_proto/combined_metrics.proto
@@ -0,0 +1,36 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto2";
+
+package soong_build_metrics;
+option go_package = "android/soong/ui/metrics/metrics_proto";
+
+import "cmd/find_input_delta/find_input_delta_proto/file_list.proto";
+
+// These field numbers are also found in the inner message declarations.
+// We verify that the values are the same, and that every enum value is checked
+// in combined_metrics_test.go.
+// Do not change this enum without also updating:
+//  - the submessage's .proto file
+//  - combined_metrics_test.go
+enum FieldNumbers {
+  FIELD_NUMBERS_UNSPECIFIED = 0;
+  FIELD_NUMBERS_FILE_LIST = 1;
+}
+
+message SoongCombinedMetrics {
+  // cmd/find_input_delta/find_input_delta_proto.FileList
+  optional android.find_input_delta_proto.FileList file_list = 1;
+}
diff --git a/ui/metrics/metrics_proto/combined_metrics_test.go b/ui/metrics/metrics_proto/combined_metrics_test.go
new file mode 100644
index 0000000..eedb12a
--- /dev/null
+++ b/ui/metrics/metrics_proto/combined_metrics_test.go
@@ -0,0 +1,33 @@
+package metrics_proto
+
+import (
+	"testing"
+
+	find_input_delta_proto "android/soong/cmd/find_input_delta/find_input_delta_proto"
+)
+
+func TestCombinedMetricsMessageNums(t *testing.T) {
+	testCases := []struct {
+		Name         string
+		FieldNumbers map[string]int32
+	}{
+		{
+			Name:         "find_input_delta_proto",
+			FieldNumbers: find_input_delta_proto.FieldNumbers_value,
+		},
+	}
+	verifiedMap := make(map[string]bool)
+	for _, tc := range testCases {
+		for k, v := range tc.FieldNumbers {
+			if FieldNumbers_value[k] != v {
+				t.Errorf("%s: Expected FieldNumbers.%s == %v, found %v", tc.Name, k, FieldNumbers_value[k], v)
+			}
+			verifiedMap[k] = true
+		}
+	}
+	for k, v := range FieldNumbers_value {
+		if !verifiedMap[k] {
+			t.Errorf("No test case verifies FieldNumbers.%s=%v", k, v)
+		}
+	}
+}
diff --git a/ui/metrics/metrics_proto/regen.sh b/ui/metrics/metrics_proto/regen.sh
index 8eb2d74..5e5f9b8 100755
--- a/ui/metrics/metrics_proto/regen.sh
+++ b/ui/metrics/metrics_proto/regen.sh
@@ -12,6 +12,6 @@
   die "could not find aprotoc. ${error_msg}"
 fi
 
-if ! aprotoc --go_out=paths=source_relative:. metrics.proto; then
+if ! aprotoc --go_out=paths=source_relative:. -I .:../../.. metrics.proto combined_metrics.proto; then
   die "build failed. ${error_msg}"
 fi