veyron.go.core: Make context.T a concrete type.

Change-Id: I1f4ce09c8a302214e13da6939a20dbf625d31511
MultiPart: 1/6
diff --git a/services/mgmt/device/impl/app_service.go b/services/mgmt/device/impl/app_service.go
index bde4143..740c859 100644
--- a/services/mgmt/device/impl/app_service.go
+++ b/services/mgmt/device/impl/app_service.go
@@ -310,7 +310,7 @@
 	return nil
 }
 
-func fetchAppEnvelope(ctx context.T, origin string) (*application.Envelope, error) {
+func fetchAppEnvelope(ctx *context.T, origin string) (*application.Envelope, error) {
 	envelope, err := fetchEnvelope(ctx, origin)
 	if err != nil {
 		return nil, err
@@ -324,7 +324,7 @@
 }
 
 // newVersion sets up the directory for a new application version.
-func newVersion(ctx context.T, installationDir string, envelope *application.Envelope, oldVersionDir string) (string, error) {
+func newVersion(ctx *context.T, installationDir string, envelope *application.Envelope, oldVersionDir string) (string, error) {
 	versionDir := filepath.Join(installationDir, generateVersionDirName())
 	if err := mkdir(versionDir); err != nil {
 		return "", verror2.Make(ErrOperationFailed, nil)
@@ -455,7 +455,7 @@
 }
 
 // setupPrincipal sets up the instance's principal, with the right blessings.
-func setupPrincipal(ctx context.T, instanceDir, versionDir string, call ipc.ServerContext, securityAgent *securityAgentState, info *instanceInfo) error {
+func setupPrincipal(ctx *context.T, instanceDir, versionDir string, call ipc.ServerContext, securityAgent *securityAgentState, info *instanceInfo) error {
 	var p security.Principal
 	if securityAgent != nil {
 		// TODO(caprita): Part of the cleanup upon destroying an
@@ -938,7 +938,7 @@
 	return i.run(veyron2.RuntimeFromContext(call.Context()).Namespace().Roots(), instanceDir, systemName)
 }
 
-func stopAppRemotely(ctx context.T, appVON string) error {
+func stopAppRemotely(ctx *context.T, appVON string) error {
 	appStub := appcycle.AppCycleClient(appVON)
 	ctx, cancel := ctx.WithTimeout(ipcContextTimeout)
 	defer cancel()
@@ -962,7 +962,7 @@
 	return nil
 }
 
-func stop(ctx context.T, instanceDir string) error {
+func stop(ctx *context.T, instanceDir string) error {
 	info, err := loadInstanceInfo(instanceDir)
 	if err != nil {
 		return err
diff --git a/services/mgmt/device/impl/callback.go b/services/mgmt/device/impl/callback.go
index c1ed6a6..174aec5 100644
--- a/services/mgmt/device/impl/callback.go
+++ b/services/mgmt/device/impl/callback.go
@@ -11,7 +11,7 @@
 
 // InvokeCallback provides the parent device manager with the given name (which
 // is expected to be this device manager's object name).
-func InvokeCallback(ctx context.T, name string) {
+func InvokeCallback(ctx *context.T, name string) {
 	handle, err := exec.GetChildHandle()
 	switch err {
 	case nil:
diff --git a/services/mgmt/device/impl/device_service.go b/services/mgmt/device/impl/device_service.go
index 22eabf8..08e9e86 100644
--- a/services/mgmt/device/impl/device_service.go
+++ b/services/mgmt/device/impl/device_service.go
@@ -152,7 +152,7 @@
 	return link, scriptPath, nil
 }
 
-func (s *deviceService) revertDeviceManager(ctx context.T) error {
+func (s *deviceService) revertDeviceManager(ctx *context.T) error {
 	if err := updateLink(s.config.Previous, s.config.CurrentLink); err != nil {
 		return err
 	}
@@ -177,7 +177,7 @@
 
 // TODO(cnicolaou): would this be better implemented using the modules
 // framework now that it exists?
-func (s *deviceService) testDeviceManager(ctx context.T, workspace string, envelope *application.Envelope) error {
+func (s *deviceService) testDeviceManager(ctx *context.T, workspace string, envelope *application.Envelope) error {
 	path := filepath.Join(workspace, "deviced.sh")
 	cmd := exec.Command(path)
 
@@ -299,7 +299,7 @@
 	return nil
 }
 
-func (s *deviceService) updateDeviceManager(ctx context.T) error {
+func (s *deviceService) updateDeviceManager(ctx *context.T) error {
 	if len(s.config.Origin) == 0 {
 		return verror2.Make(ErrUpdateNoOp, ctx)
 	}
diff --git a/services/mgmt/device/impl/impl_test.go b/services/mgmt/device/impl/impl_test.go
index 995b964..1113c34 100644
--- a/services/mgmt/device/impl/impl_test.go
+++ b/services/mgmt/device/impl/impl_test.go
@@ -757,7 +757,7 @@
 	return runtime
 }
 
-func tryInstall(ctx context.T) error {
+func tryInstall(ctx *context.T) error {
 	appsName := "dm//apps"
 	stub := device.ApplicationClient(appsName)
 	if _, err := stub.Install(ctx, mockApplicationRepoName); err != nil {
diff --git a/services/mgmt/device/impl/util.go b/services/mgmt/device/impl/util.go
index 8a83af4..fd2d7f3 100644
--- a/services/mgmt/device/impl/util.go
+++ b/services/mgmt/device/impl/util.go
@@ -23,7 +23,7 @@
 	ipcContextTimeout = time.Minute
 )
 
-func downloadBinary(ctx context.T, workspace, fileName, name string) error {
+func downloadBinary(ctx *context.T, workspace, fileName, name string) error {
 	data, _, err := binary.Download(ctx, name)
 	if err != nil {
 		vlog.Errorf("Download(%v) failed: %v", name, err)
@@ -37,7 +37,7 @@
 	return nil
 }
 
-func fetchEnvelope(ctx context.T, origin string) (*application.Envelope, error) {
+func fetchEnvelope(ctx *context.T, origin string) (*application.Envelope, error) {
 	stub := repository.ApplicationClient(origin)
 	// TODO(jsimsa): Include logic that computes the set of supported
 	// profiles.