Update some comments about the image mutator.

Test: It's just comment changes.
Change-Id: Idac69f5369caad028f3daa6aa5c1088d697c07e2

cc/cc.go

@@ -290,9 +290,15 @@ type BaseProperties struct {
 	// Set by DepsMutator.
 	AndroidMkSystemSharedLibs []string `blueprint:"mutated"`
 
+	// The name of the image this module is built for, suffixed with a '.'
 	ImageVariationPrefix string `blueprint:"mutated"`
-	VndkVersion          string `blueprint:"mutated"`
-	SubName              string `blueprint:"mutated"`
+
+	// The VNDK version this module is built against. If empty, the module is not
+	// build against the VNDK.
+	VndkVersion string `blueprint:"mutated"`
+
+	// Suffix for the name of Android.mk entries generated by this module
+	SubName string `blueprint:"mutated"`
 
 	// *.logtags files, to combine together in order to generate the /system/etc/event-log-tags
 	// file
@@ -315,12 +321,15 @@ type BaseProperties struct {
 	// Make this module available when building for recovery
 	Recovery_available *bool
 
-	// Set by imageMutator
-	CoreVariantNeeded          bool     `blueprint:"mutated"`
-	RamdiskVariantNeeded       bool     `blueprint:"mutated"`
-	VendorRamdiskVariantNeeded bool     `blueprint:"mutated"`
-	RecoveryVariantNeeded      bool     `blueprint:"mutated"`
-	ExtraVariants              []string `blueprint:"mutated"`
+	// Used by imageMutator, set by ImageMutatorBegin()
+	CoreVariantNeeded          bool `blueprint:"mutated"`
+	RamdiskVariantNeeded       bool `blueprint:"mutated"`
+	VendorRamdiskVariantNeeded bool `blueprint:"mutated"`
+	RecoveryVariantNeeded      bool `blueprint:"mutated"`
+
+	// A list of variations for the "image" mutator of the form
+	//<image name> '.' <version char>, for example, 'vendor.S'
+	ExtraVersionedImageVariations []string `blueprint:"mutated"`
 
 	// Allows this module to use non-APEX version of libraries. Useful
 	// for building binaries that are started before APEXes are activated.