Bug 633406 - Check for problems getting the cache directory on Android r=blassey, a=fennec-crash

embedding/android/GeckoAppShell.java

@@ -110,10 +110,19 @@ class GeckoAppShell
     }
 
     public static long getFreeSpace() {
-        if (sFreeSpace == -1) {
-            StatFs cacheStats = new StatFs(getCacheDir().getPath());
-            sFreeSpace = cacheStats.getFreeBlocks() * 
-                cacheStats.getBlockSize();
+        try {
+            if (sFreeSpace == -1) {
+                File cacheDir = getCacheDir();
+                if (cacheDir != null) {
+                    StatFs cacheStats = new StatFs(cacheDir.getPath());
+                    sFreeSpace = cacheStats.getFreeBlocks() * 
+                        cacheStats.getBlockSize();
+                } else {
+                    Log.i("GeckoAppShell", "Unable to get cache dir");
+                }
+            }
+        } catch (Exception e) {
+            Log.e("GeckoAppShell", "exception while stating cache dir: ", e);
         }
         return sFreeSpace;
     }