Use one mutator for all bp2build conversion.

Each conversion required defining a separate mutator, which will each
operate on _all_ modules and requires each to repeat checks whether the
mutator should operator. Instead, we introduce a single mutator and
modules can define a ConvertWithBp2build to implement bp2build
conversion for that module.

Test: bp2build.sh
Bug: 183079158
Change-Id: I99d4b51f441c2903879092c5b56313d606d4338d
diff --git a/cc/library_headers.go b/cc/library_headers.go
index ce8c391..70e4715 100644
--- a/cc/library_headers.go
+++ b/cc/library_headers.go
@@ -25,7 +25,6 @@
 	// Register sdk member types.
 	android.RegisterSdkMemberType(headersLibrarySdkMemberType)
 
-	android.RegisterBp2BuildMutator("cc_library_headers", CcLibraryHeadersBp2Build)
 }
 
 var headersLibrarySdkMemberType = &librarySdkMemberType{
@@ -96,6 +95,7 @@
 	module, library := NewLibrary(android.HostAndDeviceSupported)
 	library.HeaderOnly()
 	module.sdkMemberTypes = []android.SdkMemberType{headersLibrarySdkMemberType}
+	module.bazelable = true
 	module.bazelHandler = &libraryHeaderBazelHander{module: module, library: library}
 	return module.Init()
 }
@@ -117,21 +117,7 @@
 	System_dynamic_deps      bazel.LabelListAttribute
 }
 
-func CcLibraryHeadersBp2Build(ctx android.TopDownMutatorContext) {
-	module, ok := ctx.Module().(*Module)
-	if !ok {
-		// Not a cc module
-		return
-	}
-
-	if !module.ConvertWithBp2build(ctx) {
-		return
-	}
-
-	if ctx.ModuleType() != "cc_library_headers" {
-		return
-	}
-
+func libraryHeadersBp2Build(ctx android.TopDownMutatorContext, module *Module) {
 	baseAttributes := bp2BuildParseBaseProps(ctx, module)
 	exportedIncludes := bp2BuildParseExportedIncludes(ctx, module, baseAttributes.includes)
 	linkerAttrs := baseAttributes.linkerAttributes