Remove another reference to update.sh in docs

docs/clang.md

 # Clang
 
 [Clang](http://clang.llvm.org/) is a compiler with many desirable features
 (outlined on their website).
 
 Chrome can be built with Clang. It is now the default compiler on Mac and Linux
 for building Chrome, and it is currently useful for its warning and error
 messages on Android and Windows.
 
 See
 [the open bugs](http://code.google.com/p/chromium/issues/list?q=label:clang).
 
 [TOC]
 
 ## Build instructions
 
 Get clang (happens automatically during `gclient runhooks` on Mac and Linux):
 
-    tools/clang/scripts/update.sh
+    tools/clang/scripts/update.py
 
 (Only needs to be run once per checkout, and clang will be automatically updated
 by `gclient runhooks`.)
 
 ### Reverting to gcc on linux
 
 We don't have bots that test this, but building with gcc4.8+ should still work
 on Linux. If your system gcc is new enough, use this to build with gcc if you
 don't want to build with clang:
 
@@ skipping 91 matching lines @@
 clang_use_chrome_plugins=0 make_clang_dir=$HOME/src/llvm-build" \
 build/gyp_chromium
 ```
 
 You can then run `head out/Release/build.ninja` and check that the first to
 lines set `cc` and `cxx` to your clang binary. If things look good, run `ninja
 -C out/Release` to build.
 
 If your clang revision is very different from the one currently used in chromium
 
-*   Check `tools/clang/scripts/update.sh` to find chromium's clang revision
+*   Check `tools/clang/scripts/update.py` to find chromium's clang revision
 *   You might have to tweak warning flags. Or you could set `werror=` in the
     line above to disable warnings as errors (but this only works on Linux).