diff --git a/android/mutator.go b/android/mutator.go
index 081c2b2..cd0d152 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -115,14 +115,35 @@
 type TopDownMutatorContext interface {
 	BaseModuleContext
 
+	OtherModuleExists(name string) bool
 	Rename(name string)
+	Module() Module
+
+	OtherModuleName(m blueprint.Module) string
+	OtherModuleDir(m blueprint.Module) string
+	OtherModuleErrorf(m blueprint.Module, fmt string, args ...interface{})
+	OtherModuleDependencyTag(m blueprint.Module) blueprint.DependencyTag
 
 	CreateModule(blueprint.ModuleFactory, ...interface{})
+
+	GetDirectDepWithTag(name string, tag blueprint.DependencyTag) blueprint.Module
+	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
+
+	VisitDirectDeps(visit func(Module))
+	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
+	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
+	VisitDepsDepthFirst(visit func(Module))
+	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
+	WalkDeps(visit func(Module, Module) bool)
+	// GetWalkPath is supposed to be called in visit function passed in WalkDeps()
+	// and returns a top-down dependency path from a start module to current child module.
+	GetWalkPath() []Module
 }
 
 type topDownMutatorContext struct {
-	bp blueprint.TopDownMutatorContext
+	blueprint.TopDownMutatorContext
 	baseModuleContext
+	walkPath []Module
 }
 
 type BottomUpMutator func(BottomUpMutatorContext)
@@ -130,7 +151,9 @@
 type BottomUpMutatorContext interface {
 	BaseModuleContext
 
+	OtherModuleExists(name string) bool
 	Rename(name string)
+	Module() blueprint.Module
 
 	AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string)
 	AddReverseDependency(module blueprint.Module, tag blueprint.DependencyTag, name string)
@@ -144,7 +167,7 @@
 }
 
 type bottomUpMutatorContext struct {
-	bp blueprint.BottomUpMutatorContext
+	blueprint.BottomUpMutatorContext
 	baseModuleContext
 }
 
@@ -152,8 +175,8 @@
 	f := func(ctx blueprint.BottomUpMutatorContext) {
 		if a, ok := ctx.Module().(Module); ok {
 			actx := &bottomUpMutatorContext{
-				bp:                ctx,
-				baseModuleContext: a.base().baseModuleContextFactory(ctx),
+				BottomUpMutatorContext: ctx,
+				baseModuleContext:      a.base().baseModuleContextFactory(ctx),
 			}
 			m(actx)
 		}
@@ -167,8 +190,8 @@
 	f := func(ctx blueprint.TopDownMutatorContext) {
 		if a, ok := ctx.Module().(Module); ok {
 			actx := &topDownMutatorContext{
-				bp:                ctx,
-				baseModuleContext: a.base().baseModuleContextFactory(ctx),
+				TopDownMutatorContext: ctx,
+				baseModuleContext:     a.base().baseModuleContextFactory(ctx),
 			}
 			m(actx)
 		}
@@ -193,6 +216,99 @@
 	}
 }
 
+func (t *topDownMutatorContext) Config() Config {
+	return t.config
+}
+
+func (b *bottomUpMutatorContext) Config() Config {
+	return b.config
+}
+
+func (t *topDownMutatorContext) Module() Module {
+	module, _ := t.TopDownMutatorContext.Module().(Module)
+	return module
+}
+
+func (t *topDownMutatorContext) VisitDirectDeps(visit func(Module)) {
+	t.TopDownMutatorContext.VisitDirectDeps(func(module blueprint.Module) {
+		if aModule, _ := module.(Module); aModule != nil {
+			visit(aModule)
+		}
+	})
+}
+
+func (t *topDownMutatorContext) VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module)) {
+	t.TopDownMutatorContext.VisitDirectDeps(func(module blueprint.Module) {
+		if aModule, _ := module.(Module); aModule != nil {
+			if t.TopDownMutatorContext.OtherModuleDependencyTag(aModule) == tag {
+				visit(aModule)
+			}
+		}
+	})
+}
+
+func (t *topDownMutatorContext) VisitDirectDepsIf(pred func(Module) bool, visit func(Module)) {
+	t.TopDownMutatorContext.VisitDirectDepsIf(
+		// pred
+		func(module blueprint.Module) bool {
+			if aModule, _ := module.(Module); aModule != nil {
+				return pred(aModule)
+			} else {
+				return false
+			}
+		},
+		// visit
+		func(module blueprint.Module) {
+			visit(module.(Module))
+		})
+}
+
+func (t *topDownMutatorContext) VisitDepsDepthFirst(visit func(Module)) {
+	t.TopDownMutatorContext.VisitDepsDepthFirst(func(module blueprint.Module) {
+		if aModule, _ := module.(Module); aModule != nil {
+			visit(aModule)
+		}
+	})
+}
+
+func (t *topDownMutatorContext) VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module)) {
+	t.TopDownMutatorContext.VisitDepsDepthFirstIf(
+		// pred
+		func(module blueprint.Module) bool {
+			if aModule, _ := module.(Module); aModule != nil {
+				return pred(aModule)
+			} else {
+				return false
+			}
+		},
+		// visit
+		func(module blueprint.Module) {
+			visit(module.(Module))
+		})
+}
+
+func (t *topDownMutatorContext) WalkDeps(visit func(Module, Module) bool) {
+	t.walkPath = []Module{t.Module()}
+	t.TopDownMutatorContext.WalkDeps(func(child, parent blueprint.Module) bool {
+		childAndroidModule, _ := child.(Module)
+		parentAndroidModule, _ := parent.(Module)
+		if childAndroidModule != nil && parentAndroidModule != nil {
+			// record walkPath before visit
+			for t.walkPath[len(t.walkPath)-1] != parentAndroidModule {
+				t.walkPath = t.walkPath[0 : len(t.walkPath)-1]
+			}
+			t.walkPath = append(t.walkPath, childAndroidModule)
+			return visit(childAndroidModule, parentAndroidModule)
+		} else {
+			return false
+		}
+	})
+}
+
+func (t *topDownMutatorContext) GetWalkPath() []Module {
+	return t.walkPath
+}
+
 func (t *topDownMutatorContext) AppendProperties(props ...interface{}) {
 	for _, p := range props {
 		err := proptools.AppendMatchingProperties(t.Module().base().customizableProperties,
@@ -220,61 +336,3 @@
 		}
 	}
 }
-
-// android.topDownMutatorContext either has to embed blueprint.TopDownMutatorContext, in which case every method that
-// has an overridden version in android.BaseModuleContext has to be manually forwarded to BaseModuleContext to avoid
-// ambiguous method errors, or it has to store a blueprint.TopDownMutatorContext non-embedded, in which case every
-// non-overridden method has to be forwarded.  There are fewer non-overridden methods, so use the latter.  The following
-// methods forward to the identical blueprint versions for topDownMutatorContext and bottomUpMutatorContext.
-
-func (t *topDownMutatorContext) Rename(name string) {
-	t.bp.Rename(name)
-}
-
-func (t *topDownMutatorContext) CreateModule(factory blueprint.ModuleFactory, props ...interface{}) {
-	t.bp.CreateModule(factory, props...)
-}
-
-func (b *bottomUpMutatorContext) Rename(name string) {
-	b.bp.Rename(name)
-}
-
-func (b *bottomUpMutatorContext) AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string) {
-	b.bp.AddDependency(module, tag, name...)
-}
-
-func (b *bottomUpMutatorContext) AddReverseDependency(module blueprint.Module, tag blueprint.DependencyTag, name string) {
-	b.bp.AddReverseDependency(module, tag, name)
-}
-
-func (b *bottomUpMutatorContext) CreateVariations(variations ...string) []blueprint.Module {
-	return b.bp.CreateVariations(variations...)
-}
-
-func (b *bottomUpMutatorContext) CreateLocalVariations(variations ...string) []blueprint.Module {
-	return b.bp.CreateLocalVariations(variations...)
-}
-
-func (b *bottomUpMutatorContext) SetDependencyVariation(variation string) {
-	b.bp.SetDependencyVariation(variation)
-}
-
-func (b *bottomUpMutatorContext) AddVariationDependencies(variations []blueprint.Variation, tag blueprint.DependencyTag,
-	names ...string) {
-
-	b.bp.AddVariationDependencies(variations, tag, names...)
-}
-
-func (b *bottomUpMutatorContext) AddFarVariationDependencies(variations []blueprint.Variation,
-	tag blueprint.DependencyTag, names ...string) {
-
-	b.bp.AddFarVariationDependencies(variations, tag, names...)
-}
-
-func (b *bottomUpMutatorContext) AddInterVariantDependency(tag blueprint.DependencyTag, from, to blueprint.Module) {
-	b.bp.AddInterVariantDependency(tag, from, to)
-}
-
-func (b *bottomUpMutatorContext) ReplaceDependencies(name string) {
-	b.bp.ReplaceDependencies(name)
-}