Field initialization in TranslateURLFetcher

The field was used uninitialized what may lead to arbitrary number of unwanted
network request retries when server replies 5xx.

Change-Id: I4700d8186f81dc133b64440a392d3a916247a739
Reviewed-on: https://chromium-review.googlesource.com/564610
Commit-Queue: David Roger <droger@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485572}

components/translate/core/browser/translate_url_fetcher.cc

@@ -23,7 +23,7 @@ const int kMaxRetry = 16;
 }  // namespace
 
 TranslateURLFetcher::TranslateURLFetcher(int id)
-    : id_(id), state_(IDLE), retry_count_(0) {}
+    : id_(id), state_(IDLE), retry_count_(0), max_retry_on_5xx_(0) {}
 
 TranslateURLFetcher::~TranslateURLFetcher() {}