Update base/tools_sanity_unittest.cc to cover MSan.

base/tools_sanity_unittest.cc

Index: base/tools_sanity_unittest.cc
diff --git a/base/tools_sanity_unittest.cc b/base/tools_sanity_unittest.cc
index 4804a35a3b9ef95cec9db0327982fd394b6da30a..c763a32a53159b0aa1a5a22cf5942a3c0d83eef6 100644
--- a/base/tools_sanity_unittest.cc
+++ b/base/tools_sanity_unittest.cc
@@ -32,17 +32,26 @@ const base::subtle::Atomic32 kMagicValue = 42;
 do { if (RunningOnValgrind()) { action; } } while (0)
 #endif
 
-void ReadUninitializedValue(char *ptr) {
+void DoReadUninitializedValue(char *ptr) {
   // Comparison with 64 is to prevent clang from optimizing away the
   // jump -- valgrind only catches jumps and conditional moves, but clang uses
   // the borrow flag if the condition is just `*ptr == '\0'`.
   if (*ptr == 64) {
-    (*ptr)++;
+    VLOG(1) << "Uninit condition is true";

[Nico, 2014/01/15 17:46:18]

why this change?

   } else {
-    (*ptr)--;
+    VLOG(1) << "Uninit condition is false";
   }
 }
 
+void ReadUninitializedValue(char *ptr) {
+#if defined(MEMORY_SANITIZER)
+  EXPECT_DEATH(DoReadUninitializedValue(ptr),
+               "use-of-uninitialized-value");
+#else
+  DoReadUninitializedValue(ptr);
+#endif
+}
+
 void ReadValueOutOfArrayBoundsLeft(char *ptr) {
   char c = ptr[-2];
   VLOG(1) << "Reading a byte out of bounds: " << c;