Store the changed_inputs field in build.trace.

Bug: 323021988
Test: Manual tests
Change-Id: If5e060d13f7935ced28d556ab248f2b1e6bdb61d
diff --git a/ui/status/ninja.go b/ui/status/ninja.go
index f4e3fb8..8c3ff29 100644
--- a/ui/status/ninja.go
+++ b/ui/status/ninja.go
@@ -206,10 +206,11 @@
 		}
 		if msg.EdgeStarted != nil {
 			action := &Action{
-				Description: msg.EdgeStarted.GetDesc(),
-				Outputs:     msg.EdgeStarted.Outputs,
-				Inputs:      msg.EdgeStarted.Inputs,
-				Command:     msg.EdgeStarted.GetCommand(),
+				Description:   msg.EdgeStarted.GetDesc(),
+				Outputs:       msg.EdgeStarted.Outputs,
+				Inputs:        msg.EdgeStarted.Inputs,
+				Command:       msg.EdgeStarted.GetCommand(),
+				ChangedInputs: msg.EdgeStarted.ChangedInputs,
 			}
 			n.status.StartAction(action)
 			running[msg.EdgeStarted.GetId()] = action
diff --git a/ui/status/ninja_frontend/frontend.pb.go b/ui/status/ninja_frontend/frontend.pb.go
index d8344c8..fce7ca2 100644
--- a/ui/status/ninja_frontend/frontend.pb.go
+++ b/ui/status/ninja_frontend/frontend.pb.go
@@ -363,6 +363,8 @@
 	Command *string `protobuf:"bytes,6,opt,name=command" json:"command,omitempty"`
 	// Edge uses console.
 	Console *bool `protobuf:"varint,7,opt,name=console" json:"console,omitempty"`
+	// Changed inputs.
+	ChangedInputs []string `protobuf:"bytes,8,rep,name=changed_inputs,json=changedInputs" json:"changed_inputs,omitempty"`
 }
 
 func (x *Status_EdgeStarted) Reset() {
@@ -446,6 +448,13 @@
 	return false
 }
 
+func (x *Status_EdgeStarted) GetChangedInputs() []string {
+	if x != nil {
+		return x.ChangedInputs
+	}
+	return nil
+}
+
 type Status_EdgeFinished struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -678,7 +687,7 @@
 
 var file_frontend_proto_rawDesc = []byte{
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+	0x34, 0x0a, 0x05, 0x4c, 0x65, 0x76, 0x65, 0x6c, 0x12, 0x08, 0x0a, 0x04, 0x49, 0x4e, 0x46, 0x4f,
+	0x10, 0x00, 0x12, 0x0b, 0x0a, 0x07, 0x57, 0x41, 0x52, 0x4e, 0x49, 0x4e, 0x47, 0x10, 0x01, 0x12,
+	0x09, 0x0a, 0x05, 0x45, 0x52, 0x52, 0x4f, 0x52, 0x10, 0x02, 0x12, 0x09, 0x0a, 0x05, 0x44, 0x45,
+	0x42, 0x55, 0x47, 0x10, 0x03, 0x42, 0x2a, 0x48, 0x03, 0x5a, 0x26, 0x61, 0x6e, 0x64, 0x72, 0x6f,
+	0x69, 0x64, 0x2f, 0x73, 0x6f, 0x6f, 0x6e, 0x67, 0x2f, 0x75, 0x69, 0x2f, 0x73, 0x74, 0x61, 0x74,
+	0x75, 0x73, 0x2f, 0x6e, 0x69, 0x6e, 0x6a, 0x61, 0x5f, 0x66, 0x72, 0x6f, 0x6e, 0x74, 0x65, 0x6e,
+	0x64,
 }
 
 var (
diff --git a/ui/status/ninja_frontend/frontend.proto b/ui/status/ninja_frontend/frontend.proto
index 42b251b..faa0d34 100644
--- a/ui/status/ninja_frontend/frontend.proto
+++ b/ui/status/ninja_frontend/frontend.proto
@@ -54,6 +54,8 @@
     optional string command = 6;
     // Edge uses console.
     optional bool console = 7;
+    // Changed inputs since last build.
+    repeated string changed_inputs = 8;
   }
 
   message EdgeFinished {
diff --git a/ui/status/status.go b/ui/status/status.go
index da78994..52ed56a 100644
--- a/ui/status/status.go
+++ b/ui/status/status.go
@@ -41,6 +41,10 @@
 	// It's optional, but one of either Description or Command should be
 	// set.
 	Command string
+
+	// ChangedInputs is the (optional) list of inputs that have changed
+	// since last time this action was run.
+	ChangedInputs []string
 }
 
 // ActionResult describes the result of running an Action.
diff --git a/ui/tracer/status.go b/ui/tracer/status.go
index f973613..8acf561 100644
--- a/ui/tracer/status.go
+++ b/ui/tracer/status.go
@@ -15,9 +15,10 @@
 package tracer
 
 import (
-	"android/soong/ui/status"
 	"strings"
 	"time"
+
+	"android/soong/ui/status"
 )
 
 func (t *tracerImpl) StatusTracer() status.StatusOutput {
@@ -110,6 +111,7 @@
 			VoluntaryContextSwitches:   result.Stats.VoluntaryContextSwitches,
 			InvoluntaryContextSwitches: result.Stats.InvoluntaryContextSwitches,
 			Tags:                       s.parseTags(result.Stats.Tags),
+			ChangedInputs:              result.Action.ChangedInputs,
 		},
 	})
 }
@@ -125,6 +127,7 @@
 	VoluntaryContextSwitches   uint64            `json:"voluntary_context_switches"`
 	InvoluntaryContextSwitches uint64            `json:"involuntary_context_switches"`
 	Tags                       map[string]string `json:"tags"`
+	ChangedInputs              []string          `json:"changed_inputs"`
 }
 
 func (s *statusOutput) Flush()                                        {}