Ignore files with non-sane filenames in the Android stack symbolizing tool.

BUG=498683

Review URL: https://codereview.chromium.org/1175033002

Cr-Commit-Position: refs/heads/master@{#333798}

third_party/android_platform/README.chromium

@@ -26,7 +26,8 @@ include, but are not limited to, the following:
 Added memoization of addr2line and objdump.
 Added option to change the amount of symbolization done.
 Updated output directories to use environment variable.
-When calling addr2line, check the symbol is a file (and not a directory).
+When calling addr2line, check the symbol is a file that looks like it contains
+    symbols.
 Added support for parsing LOG(FATAL) and DCHECK errors and their
     stack traces, as emitted by src/base/debug/stack_trace_android.cc
 Added support for finding symbols when library is loaded directly from the APK.

third_party/android_platform/development/scripts/symbol.py

@@ -452,6 +452,9 @@ def CallAddr2LineForSet(lib, unique_addrs):
 
 
   symbols = SYMBOLS_DIR + lib
+  if not os.path.splitext(symbols)[1] in ['', '.so', '.apk']:
+    return None
+
   if not os.path.isfile(symbols):
     return None