Rename source_prereqs to inputs in the GN build.

tools/gn/target_generator.cc

Index: tools/gn/target_generator.cc
diff --git a/tools/gn/target_generator.cc b/tools/gn/target_generator.cc
index 084c587c9838ed0b5e7b5d513dcecf0fb6db3887..252d9822571c08eb7ad7afd350d2e7e1118cef8e 100644
--- a/tools/gn/target_generator.cc
+++ b/tools/gn/target_generator.cc
@@ -163,10 +163,10 @@ void TargetGenerator::FillPublic() {
 void TargetGenerator::FillInputs() {
   const Value* value = scope_->GetValue(variables::kInputs, true);
   if (!value) {
-    // Older versions used "source_prereqs". Allow use of this variable until
+    // Older versions used "inputs". Allow use of this variable until
     // all callers are updated.
     // TODO(brettw) remove this eventually.
-    value = scope_->GetValue("source_prereqs", true);
+    value = scope_->GetValue("inputs", true);
 
     if (!value)
       return;