roll clang 159409:160967

* Lets -Wunused-private-field find more stuff 
* Fixes an ASan problem on precise 
* Improves the plugin's handling of inner classes (off by default, 
can be enabled with |-Xclang -plugin-arg-find-bad-constructs 
-Xclang check-inner-classes|) 
* Makes addr2line much faster on linux

BUG=139346
TBR=mark for base (the change was reviewed as part of https://chromiumcodereview.appspot.com/10833055/)

Review URL: https://chromiumcodereview.appspot.com/10825104

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149286 0039d316-1c4b-4281-b951-d872f2087c98

base/process_util_unittest.cc

@@ -504,6 +504,7 @@ TEST_F(ProcessUtilTest, MacMallocFailureDoesNotTerminate) {
 TEST_F(ProcessUtilTest, MacTerminateOnHeapCorruption) {
   // Assert that freeing an unallocated pointer will crash the process.
   char buf[3];
+  asm("" : "=r" (buf));  // Prevent clang from being too smart.
 #if !defined(ADDRESS_SANITIZER)
   ASSERT_DEATH(free(buf), "being freed.*"
       "\\*\\*\\* set a breakpoint in malloc_error_break to debug.*"

chrome/common/mac/objc_zombie.mm

@@ -25,7 +25,10 @@
 // Deallocated objects are re-classed as |CrZombie|.  No superclass
 // because then the class would have to override many/most of the
 // inherited methods (|NSObject| is like a category magnet!).
-@interface CrZombie {
+// Without the __attribute__, clang's -Wobjc-root-class warns on the missing
+// superclass.
+__attribute__((objc_root_class))
+@interface CrZombie  {
   Class isa;
 }
 @end

tools/clang/scripts/update.sh

@@ -8,7 +8,7 @@
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION=159409
+CLANG_REVISION=160967
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"