Fix a false valgrind uninit error under clang.

Given "if (!stun || type == STUN_DATA_INDICATION)", clang's optimizer evaluates
both sides of the ||.  Under -fno-omit-frame-pointer, this makes valgrind
unhappy. (http://build.chromium.org/p/chromium.memory.fyi/builders/Chromium%20Mac%20%28valgrind%29%282%29/builds/24355; I reproduced on linux under clang where valgrind gives line numbers.)

You can see the effect using the following program:

#include <stdio.h>
__attribute__((noinline)) bool InitializeIf(volatile bool cond, int* var) {
  if (!cond)
    return false;
  *var = 3;
  return true;
}
int main() {
  int var;
  bool initted = InitializeIf(false, &var);
  if (!initted || var == 2)
    printf("Yep.\n");
}

The fix is to initialize |type|.

r229975 seems to have exposed this, but didn't do anything to cause it.

R=hubbe@chromium.org
TBR=hclam@chromium.org

Review URL: https://codereview.chromium.org/34383003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230099 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230099