Slight code change to make some global variables const.

chrome/tools/build/win/dependencies.py

Index: chrome/tools/build/win/dependencies.py
===================================================================
--- chrome/tools/build/win/dependencies.py	(revision 11293)
+++ chrome/tools/build/win/dependencies.py	(working copy)
@@ -157,11 +157,12 @@
   except:
     raise Error("Failed to load " + list_file)
 
-  # The dependency files have dependencies in two section - dependents and delay_loaded
-  # Also various distributions of Chromium can have different dependencies. So first
-  # we read generic dependencies ("dependents" and "delay_loaded"). If distribution
-  # specific dependencies exist (i.e. "dependents_google_chrome" and
-  # "delay_loaded_google_chrome") we use those instead.
+  # The dependency files have dependencies in two section - dependents and
+  # delay_loaded. Also various distributions of Chromium can have different
+  # dependencies. So first we read generic dependencies ("dependents" and
+  # "delay_loaded"). If distribution specific dependencies exist
+  # (i.e. "dependents_google_chrome" and "delay_loaded_google_chrome") we use
+  # those instead.
   distribution = DIST_DEFAULT
   if DIST_ENV_VAR in os.environ.keys():
     distribution = os.environ[DIST_ENV_VAR].lower()