ake string_util::WriteInto() DCHECK() that the supplied |length_with_null| > 1, meaning that the without-'\0' string is non-empty.  This replaces the conditional code added recently that makes this case return NULL.  It's easier to understand if it's simply an error to call WriteInto() in this case at all.

Add DCHECK()s or conditionals as appropriate to callers in order to ensure this assertion holds.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/8418034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@112005 0039d316-1c4b-4281-b951-d872f2087c98

diff --git a/base/rand_util_unittest.cc b/base/rand_util_unittest.cc
index a3474ba..e0e85ecaa 100644
--- a/base/rand_util_unittest.cc
+++ b/base/rand_util_unittest.cc

@@ -41,8 +41,8 @@
 }
 
 TEST(RandUtilTest, RandBytesAsString) {
-  std::string random_string = base::RandBytesAsString(0);
-  EXPECT_EQ(0U, random_string.size());
+  std::string random_string = base::RandBytesAsString(1);
+  EXPECT_EQ(1U, random_string.size());
   random_string = base::RandBytesAsString(145);
   EXPECT_EQ(145U, random_string.size());
   char accumulator = 0;