Rename common to android

Rename the "common" package to "android", because common is too
generic.  Also removes all android.Android naming stutter.

Ran:
gomvpkg -from 'android/soong/common' -to 'android/soong/android'
gorename -from '"android/soong/android".AndroidModuleContext' -to 'ModuleContext'
gorename -from '"android/soong/android".AndroidBaseContext' -to 'BaseContext'
gorename -from '"android/soong/android".AndroidModuleBase' -to 'ModuleBase'
gorename -from '"android/soong/android".AndroidBottomUpMutatorContext' -to 'BottomUpMutatorContext'
gorename -from '"android/soong/android".AndroidTopDownMutatorContext' -to 'TopDownMutatorContext'
gorename -from '"android/soong/android".AndroidModule' -to 'Module'

Change-Id: I3b23590b8ce7c8a1ea1139411d84a53163288da7

android/defaults.go

@@ -0,0 +1,133 @@
+// 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 (
+	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
+)
+
+type defaultsDependencyTag struct {
+	blueprint.BaseDependencyTag
+}
+
+var DefaultsDepTag defaultsDependencyTag
+
+type defaultsProperties struct {
+	Defaults []string
+}
+
+type DefaultableModule struct {
+	defaultsProperties    defaultsProperties
+	defaultableProperties []interface{}
+}
+
+func (d *DefaultableModule) defaults() *defaultsProperties {
+	return &d.defaultsProperties
+}
+
+func (d *DefaultableModule) setProperties(props []interface{}) {
+	d.defaultableProperties = props
+}
+
+type Defaultable interface {
+	defaults() *defaultsProperties
+	setProperties([]interface{})
+	applyDefaults(TopDownMutatorContext, Defaults)
+}
+
+var _ Defaultable = (*DefaultableModule)(nil)
+
+func InitDefaultableModule(module Module, d Defaultable,
+	props ...interface{}) (blueprint.Module, []interface{}) {
+
+	d.setProperties(props)
+
+	props = append(props, d.defaults())
+
+	return module, props
+}
+
+type DefaultsModule struct {
+	defaultProperties []interface{}
+}
+
+type Defaults interface {
+	isDefaults() bool
+	setProperties([]interface{})
+	properties() []interface{}
+}
+
+func (d *DefaultsModule) isDefaults() bool {
+	return true
+}
+
+func (d *DefaultsModule) properties() []interface{} {
+	return d.defaultProperties
+}
+
+func (d *DefaultsModule) setProperties(props []interface{}) {
+	d.defaultProperties = props
+}
+
+func InitDefaultsModule(module Module, d Defaults, props ...interface{}) (blueprint.Module, []interface{}) {
+	d.setProperties(props)
+
+	return module, props
+}
+
+var _ Defaults = (*DefaultsModule)(nil)
+
+func (defaultable *DefaultableModule) applyDefaults(ctx TopDownMutatorContext,
+	defaults Defaults) {
+
+	for _, prop := range defaultable.defaultableProperties {
+		for _, def := range defaults.properties() {
+			if proptools.TypeEqual(prop, def) {
+				err := proptools.PrependProperties(prop, def, nil)
+				if err != nil {
+					if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok {
+						ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error())
+					} else {
+						panic(err)
+					}
+				}
+			}
+		}
+	}
+}
+
+func defaultsDepsMutator(ctx BottomUpMutatorContext) {
+	if defaultable, ok := ctx.Module().(Defaultable); ok {
+		ctx.AddDependency(ctx.Module(), DefaultsDepTag, defaultable.defaults().Defaults...)
+	}
+}
+
+func defaultsMutator(ctx TopDownMutatorContext) {
+	if defaultable, ok := ctx.Module().(Defaultable); ok {
+		for _, defaultsDep := range defaultable.defaults().Defaults {
+			ctx.VisitDirectDeps(func(m blueprint.Module) {
+				if ctx.OtherModuleName(m) == defaultsDep {
+					if defaultsModule, ok := m.(Defaults); ok {
+						defaultable.applyDefaults(ctx, defaultsModule)
+					} else {
+						ctx.PropertyErrorf("defaults", "module %s is not an defaults module",
+							ctx.OtherModuleName(m))
+					}
+				}
+			})
+		}
+	}
+}