[Mac/GN] Fix rebuilds when changing framework_version of a mac_framework_bundle.

build/config/mac/rules.gni

Index: build/config/mac/rules.gni
diff --git a/build/config/mac/rules.gni b/build/config/mac/rules.gni
index c10cc4b7f940dbefbba18126ee5e8454eca43d77..81297eb9a3d396bd5d7c5e2debfcab2cb87bf811 100644
--- a/build/config/mac/rules.gni
+++ b/build/config/mac/rules.gni
@@ -258,11 +258,13 @@ template("mac_framework_bundle") {
   # the versioned directory structure.
   _framework_target = _target_name
   _framework_name = _output_name + ".framework"
-  _framework_root_dir = "$root_out_dir/$_framework_name"
+  _framework_base_dir = "$root_out_dir/$_framework_name"
   if (defined(invoker.framework_version) && invoker.framework_version != "") {
     _framework_version = invoker.framework_version
-    _framework_root_dir += "/Versions/$_framework_version"
+    _framework_root_dir = _framework_base_dir + "/Versions/$_framework_version"
     _framework_target = _target_name + "_create_bundle"
+  } else {
+    _framework_root_dir = _framework_base_dir
   }
 
   _link_shared_library_target = target_name + "_shared_library"
@@ -302,6 +304,19 @@ template("mac_framework_bundle") {
     ]
   }
 
+  # Clean the entire framework if the framework_version changes.
+  _version_arg = ""
+  if (defined(_framework_version)) {
+    _version_arg = _framework_version
+  }
+  _version_file = "$target_out_dir/${target_name}_version"
+  exec_script("//build/config/mac/prepare_framework_version.py",
+              [
+                rebase_path(_version_file),
+                rebase_path(_framework_base_dir),
+                "'$_version_arg'",

[brettw, 2016/10/27 19:30:16]

Are you sure you need to use single-quotes here? I thought GN should quote as
necessary to avoid the shell breaking args.

[Robert Sesek, 2016/10/27 20:47:00]

GN's quoting is correct. But the framework_version may be "" and it makes it
easier to see on the command line if it's explicitly quoted.

+              ])
+
   _framework_public_config = _target_name + "_public_config"
   config(_framework_public_config) {
     # TODO(sdefresne): should we have a framework_dirs similar to lib_dirs