Rename BuildDir and NinjaBuildDir.

These are just out/ and out/soong/ and the old names were quite
confusing.

Test: Presubmits.
Merged-In: I999ca62162062f27e449f83ffb00fa580d4065b8
Merged-In: I2fcd80a9e376a6842a06aa104a9f6f5c5e16f8c7
Change-Id: Ib481d2aac40df8da1b74174dc8ec576c1cb48be0
diff --git a/android/singleton.go b/android/singleton.go
index bb6614d..7ff96c9 100644
--- a/android/singleton.go
+++ b/android/singleton.go
@@ -54,10 +54,10 @@
 
 	RequireNinjaVersion(major, minor, micro int)
 
-	// SetNinjaBuildDir sets the value of the top-level "builddir" Ninja variable
+	// SetOutDir sets the value of the top-level "builddir" Ninja variable
 	// that controls where Ninja stores its build log files.  This value can be
 	// set at most one time for a single build, later calls are ignored.
-	SetNinjaBuildDir(pctx PackageContext, value string)
+	SetOutDir(pctx PackageContext, value string)
 
 	// Eval takes a string with embedded ninja variables, and returns a string
 	// with all of the variables recursively expanded. Any variables references
@@ -180,8 +180,8 @@
 	addPhony(s.Config(), name, deps...)
 }
 
-func (s *singletonContextAdaptor) SetNinjaBuildDir(pctx PackageContext, value string) {
-	s.SingletonContext.SetNinjaBuildDir(pctx.PackageContext, value)
+func (s *singletonContextAdaptor) SetOutDir(pctx PackageContext, value string) {
+	s.SingletonContext.SetOutDir(pctx.PackageContext, value)
 }
 
 func (s *singletonContextAdaptor) Eval(pctx PackageContext, ninjaStr string) (string, error) {