[MIPS] Add DEBUG_BREAK() for MIPS architecture.

Small change to add correct asm break instruction for MIPS architecture.

BUG= https://code.google.com/p/chromium/issues/detail?id=130022
TEST=make chrome

Review URL: https://chromiumcodereview.appspot.com/10834234

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150789 0039d316-1c4b-4281-b951-d872f2087c98

base/debug/debugger_posix.cc

@@ -222,6 +222,8 @@ bool BeingDebugged() {
 // ARM && !ANDROID
 #define DEBUG_BREAK() asm("bkpt 0")
 #endif
+#elif defined(ARCH_CPU_MIPS_FAMILY)
+#define DEBUG_BREAK() asm("break 2")
 #else
 #define DEBUG_BREAK() asm("int3")
 #endif