Consolidate *MutatorContext and ModuleContext into BaseModuleContext

Following 99bdb2ab4fd5168a71a20aecf10611425be47ec4 in build/blueprint,
move more methods into BaseModuleContext.

This reapplies I9f8df94f1ae2b55d3cccf7b9468247f3e7cb2ebd after fixing
missing errors thrown for missing defaults modules when
AllowMissingDependencies == true.

Test: m checkbuild
Test: defaults_test.go
Change-Id: Ia17b2bcbf2bac6889c419b2e73953946f6aa40ad
diff --git a/android/mutator_test.go b/android/mutator_test.go
new file mode 100644
index 0000000..4cef400
--- /dev/null
+++ b/android/mutator_test.go
@@ -0,0 +1,99 @@
+// Copyright 2015 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.
+
+package android
+
+import (
+	"io/ioutil"
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/google/blueprint/proptools"
+)
+
+type mutatorTestModule struct {
+	ModuleBase
+	props struct {
+	}
+
+	missingDeps []string
+}
+
+func mutatorTestModuleFactory() Module {
+	module := &mutatorTestModule{}
+	module.AddProperties(&module.props)
+	InitAndroidModule(module)
+	return module
+}
+
+func (m *mutatorTestModule) GenerateAndroidBuildActions(ctx ModuleContext) {
+	ctx.Build(pctx, BuildParams{
+		Rule:   Touch,
+		Output: PathForModuleOut(ctx, "output"),
+	})
+
+	m.missingDeps = ctx.GetMissingDependencies()
+}
+
+func (m *mutatorTestModule) DepsMutator(ctx BottomUpMutatorContext) {
+	ctx.AddDependency(ctx.Module(), nil, "regular_missing_dep")
+}
+
+func addMissingDependenciesMutator(ctx TopDownMutatorContext) {
+	ctx.AddMissingDependencies([]string{"added_missing_dep"})
+}
+
+func TestMutatorAddMissingDependencies(t *testing.T) {
+	buildDir, err := ioutil.TempDir("", "soong_mutator_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(buildDir)
+
+	config := TestConfig(buildDir, nil)
+	config.TestProductVariables.Allow_missing_dependencies = proptools.BoolPtr(true)
+
+	ctx := NewTestContext()
+	ctx.SetAllowMissingDependencies(true)
+
+	ctx.RegisterModuleType("test", ModuleFactoryAdaptor(mutatorTestModuleFactory))
+	ctx.PreDepsMutators(func(ctx RegisterMutatorsContext) {
+		ctx.TopDown("add_missing_dependencies", addMissingDependenciesMutator)
+	})
+
+	bp := `
+		test {
+			name: "foo",
+		}
+	`
+
+	mockFS := map[string][]byte{
+		"Android.bp": []byte(bp),
+	}
+
+	ctx.MockFileSystem(mockFS)
+
+	ctx.Register()
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	FailIfErrored(t, errs)
+
+	foo := ctx.ModuleForTests("foo", "").Module().(*mutatorTestModule)
+
+	if g, w := foo.missingDeps, []string{"added_missing_dep", "regular_missing_dep"}; !reflect.DeepEqual(g, w) {
+		t.Errorf("want foo missing deps %q, got %q", w, g)
+	}
+}