Revert "Add override_module."

This reverts commit aa65e17016152d0d73cd10ab3987bc3bd5c2ef91.

Reason for revert: Not compatible with PRODUCT_PACKAGES, and so has very limited use.

Change-Id: Ib141d3984a6f12bb50989e66037494c466b066f1
diff --git a/android/config.go b/android/config.go
index 33986f7..24be10a 100644
--- a/android/config.go
+++ b/android/config.go
@@ -895,30 +895,16 @@
 }
 
 func (c *deviceConfig) OverrideManifestPackageNameFor(name string) (manifestName string, overridden bool) {
-	if newManifestName, overridden := c.manifestPackageNameOverrides().Load(name); overridden {
-		return newManifestName.(string), true
-	}
 	return findOverrideValue(c.config.productVariables.ManifestPackageNameOverrides, name,
 		"invalid override rule %q in PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES should be <module_name>:<manifest_name>")
 }
 
 func (c *deviceConfig) OverrideCertificateFor(name string) (certificatePath string, overridden bool) {
-	if newCert, overridden := c.certificateOverrides().Load(name); overridden {
-		return newCert.(string), true
-	}
-	newCert, overridden := findOverrideValue(c.config.productVariables.CertificateOverrides, name,
+	return findOverrideValue(c.config.productVariables.CertificateOverrides, name,
 		"invalid override rule %q in PRODUCT_CERTIFICATE_OVERRIDES should be <module_name>:<certificate_module_name>")
-	if overridden {
-		// PRODUCT_CERTIFICATE_OVERRIDES only supports cert modules.
-		newCert = ":" + newCert
-	}
-	return newCert, overridden
 }
 
 func (c *deviceConfig) OverridePackageNameFor(name string) string {
-	if newName, overridden := c.moduleNameOverrides().Load(name); overridden {
-		return newName.(string)
-	}
 	newName, overridden := findOverrideValue(
 		c.config.productVariables.PackageNameOverrides,
 		name,
diff --git a/android/override_module.go b/android/override_module.go
deleted file mode 100644
index 9fe5f21..0000000
--- a/android/override_module.go
+++ /dev/null
@@ -1,97 +0,0 @@
-package android
-
-import (
-	"github.com/google/blueprint/proptools"
-	"sync"
-)
-
-func init() {
-	RegisterModuleType("override_module", OverrideModuleFactory)
-}
-
-type OverrideModule struct {
-	ModuleBase
-	properties OverrideModuleProperties
-}
-
-type OverrideModuleProperties struct {
-	// base module to override
-	Base *string
-
-	// file path or module name (in the form ":module") of a certificate to override with
-	Certificate *string
-
-	// manifest package name to override with
-	Manifest_package_name *string
-}
-
-// TODO(jungjw): Work with the mainline team to see if we can deprecate all PRODUCT_*_OVERRIDES vars
-// and hand over overriding values directly to base module code.
-func processOverrides(ctx LoadHookContext, p *OverrideModuleProperties) {
-	base := proptools.String(p.Base)
-	if base == "" {
-		ctx.PropertyErrorf("base", "base module name must be provided")
-	}
-
-	config := ctx.DeviceConfig()
-	if other, loaded := config.moduleNameOverrides().LoadOrStore(base, ctx.ModuleName()); loaded {
-		ctx.ModuleErrorf("multiple overriding modules for %q, the other: %q", base, other.(string))
-	}
-
-	if p.Certificate != nil {
-		config.certificateOverrides().Store(base, *p.Certificate)
-	}
-
-	if p.Manifest_package_name != nil {
-		config.manifestPackageNameOverrides().Store(base, *p.Manifest_package_name)
-	}
-}
-
-func (i *OverrideModule) DepsMutator(ctx BottomUpMutatorContext) {
-	base := *i.properties.Base
-	// Right now, we add a dependency only to check the base module exists, and so are not using a tag here.
-	// TODO(jungjw): Add a tag and check the base module type once we finalize supported base module types.
-	ctx.AddDependency(ctx.Module(), nil, base)
-}
-
-func (i *OverrideModule) GenerateAndroidBuildActions(ctx ModuleContext) {
-	// All the overrides happen in the base module.
-	// TODO(jungjw): Check the base module type.
-}
-
-// override_module overrides an existing module with the specified properties.
-//
-// Currently, only android_app is officially supported.
-func OverrideModuleFactory() Module {
-	m := &OverrideModule{}
-	AddLoadHook(m, func(ctx LoadHookContext) {
-		processOverrides(ctx, &m.properties)
-	})
-	m.AddProperties(&m.properties)
-	InitAndroidModule(m)
-	return m
-}
-
-var moduleNameOverridesKey = NewOnceKey("moduleNameOverrides")
-
-func (c *deviceConfig) moduleNameOverrides() *sync.Map {
-	return c.Once(moduleNameOverridesKey, func() interface{} {
-		return &sync.Map{}
-	}).(*sync.Map)
-}
-
-var certificateOverridesKey = NewOnceKey("certificateOverrides")
-
-func (c *deviceConfig) certificateOverrides() *sync.Map {
-	return c.Once(certificateOverridesKey, func() interface{} {
-		return &sync.Map{}
-	}).(*sync.Map)
-}
-
-var manifestPackageNameOverridesKey = NewOnceKey("manifestPackageNameOverrides")
-
-func (c *deviceConfig) manifestPackageNameOverrides() *sync.Map {
-	return c.Once(manifestPackageNameOverridesKey, func() interface{} {
-		return &sync.Map{}
-	}).(*sync.Map)
-}