Add brillo cflags

Add __BRILLO__ to global cflags when building for a brillo product.

Bug: 26165350
Change-Id: I0100a8821b763075d1873d0d48fd5bd217afb580

cc/cc.go

@@ -581,6 +581,10 @@ func (c *CCBase) collectFlags(ctx common.AndroidModuleContext, toolchain Toolcha
 				fmt.Sprintf("${%sGlobalCflags}", ctx.HostOrDevice()))
 		}
 
+		if Bool(ctx.AConfig().ProductVariables.Brillo) {
+			flags.GlobalFlags = append(flags.GlobalFlags, "-D__BRILLO__")
+		}
+
 		if ctx.Device() {
 			if Bool(c.Properties.Rtti) {
 				flags.CppFlags = append(flags.CppFlags, "-frtti")

common/variable.go

@@ -82,6 +82,7 @@ type productVariables struct {
 	CrossHostSecondaryArch *string `json:",omitempty"`
 
 	Unbundled_build *bool `json:",omitempty"`
+	Brillo          *bool `json:",omitempty"`
 }
 
 func boolPtr(v bool) *bool {