Instead of always running the LASTCHANGE extractor, run it with regular file dependencies.

During gclient runhooks, update LASTCHANGE so that it will be updated at least as often as runhooks is run (i.e. for every sync).

LASTCHANGE moved to build/util rather than SHARED_INTERMEDIATE_DIR because that directory isn't known to runhooks.

BUG=111731

Review URL: https://chromiumcodereview.appspot.com/9169105

git-svn-id: http://src.chromium.org/svn/trunk/src/build@119950 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

util/build_util.gyp

@@ -8,7 +8,7 @@
       'target_name': 'lastchange',
       'type': 'none',
       'variables': {
-        'lastchange_out_path': '<(SHARED_INTERMEDIATE_DIR)/build/LASTCHANGE',
+        'lastchange_out_path': '<(DEPTH)/build/util/LASTCHANGE',
         'default_lastchange_path': '../LASTCHANGE.in',
       },
       'actions': [
@@ -20,7 +20,6 @@
             './lastchange.py',
           ],
           'outputs': [
-            '<(lastchange_out_path).always',
             '<(lastchange_out_path)',
           ],
           'action': [