GN: Refine 'complete' static library handling

tools/gn/variables.cc

Index: tools/gn/variables.cc
diff --git a/tools/gn/variables.cc b/tools/gn/variables.cc
index dc0316b45134f1101dafda6cfd26118d1880d1bd..743845534437e518816b0d1eac8f2295907b0959 100644
--- a/tools/gn/variables.cc
+++ b/tools/gn/variables.cc
@@ -664,9 +664,11 @@ const char kCompleteStaticLib_Help[] =
     "  In some cases the static library might be the final desired output.\n"
     "  For example, you may be producing a static library for distribution to\n"
     "  third parties. In this case, the static library should include code\n"
-    "  for all dependencies in one complete package. Since GN does not unpack\n"
-    "  static libraries to forward their contents up the dependency chain,\n"
-    "  it is an error for complete static libraries to depend on other static\n"
+    "  for all dependencies in one complete package. However, complete static\n"
+    "  libraries themselves are never linked into other complete static\n"
+    "  libraries. All complete static libraries are for distribution and\n"
+    "  linking them in would cause code duplication in this case. If the\n"
+    "  static library is not for distribution, it should not be complete.\n"
     "\n"
     "  In rare cases it makes sense to list a header in more than one\n"

[brettw, 2016/04/21 20:47:00]

Can you add a new paragraph here on the "promotion to source set" aspect of
linking a non-complete static library into a complete one?

     "  target if it could be considered conceptually a member of both.\n"