roll clang 155835:159409

First clang roll in a few weeks, so lots of new stuff:

* better 'unused' warnings. Now catches e.g. "AutoLock(&lock);"
* better 'uninitialized' warnings
* template type eliding in diagnostics
* TLS attribute support
* New -Wunused-private-field warning (disabled for now)
* style plugin has better warning for implicit destructors
* method_iterator interface changed back to what it was, update plugin again
* Warn on member variable self assignments

BUG=135207
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10689041

git-svn-id: http://src.chromium.org/svn/trunk/src/build@145022 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -2233,6 +2233,9 @@
               # Warns on switches on enums that cover all enum values but
               # also contain a default: branch. Chrome is full of that.
               '-Wno-covered-switch-default',
+
+              # TODO(thakis): Remove once the patch to fix violations is in.
+              '-Wno-unused-private-field',
             ],
             'cflags!': [
               # Clang doesn't seem to know know this flag.
@@ -2689,6 +2692,9 @@
                 # Warns on switches on enums that cover all enum values but
                 # also contain a default: branch. Chrome is full of that.
                 '-Wno-covered-switch-default',
+
+                # TODO(thakis): Remove once the patch to fix violations is in.
+                '-Wno-unused-private-field',
               ],
             }],
             ['clang==1 and clang_use_chrome_plugins==1', {