Fix test slowness introduced by https://codereview.chromium.org/2771793003

chrome/browser/android/webapk/webapk_icon_hasher.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/webapk/webapk_icon_hasher.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "net/base/data_url.h"
@@ skipping 21 matching lines @@
   return base::Uint64ToString(hash);
 }
 
 }  // anonymous namespace
 
 // static
 void WebApkIconHasher::DownloadAndComputeMurmur2Hash(
     net::URLRequestContextGetter* request_context_getter,
     const GURL& icon_url,
     const Murmur2HashCallback& callback) {
+  DownloadAndComputeMurmur2HashWithTimeout(request_context_getter, icon_url,
+                                           kDownloadTimeoutInMilliseconds,
+                                           callback);
+}
+
+// static
+void WebApkIconHasher::DownloadAndComputeMurmur2HashWithTimeout(

[dominickn, 2017/04/19 00:04:07]

Nit: I would call this DownloadAndComputeMurmur2HashForTesting, since this is
intended as a test-only method and prod code should always call the other
version.

[pkotwicz, 2017/04/19 20:34:52]

I don't thinkat that DownloadAndComputeMurmur2HashForTesting() is a good name.

Prod should not call this function directly. However, the prod version of the
function calls this function 

+    net::URLRequestContextGetter* request_context_getter,
+    const GURL& icon_url,
+    int timeout_ms,
+    const Murmur2HashCallback& callback) {
   if (!icon_url.is_valid()) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback, ""));
     return;
   }
 
   if (icon_url.SchemeIs(url::kDataScheme)) {
     std::string mime_type, char_set, data;
     std::string hash;
     if (net::DataURL::Parse(icon_url, &mime_type, &char_set, &data) &&
         !data.empty()) {
       hash = ComputeMurmur2Hash(data);
     }
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback, hash));
     return;
   }
 
   // The icon hasher will delete itself when it is done.
-  new WebApkIconHasher(request_context_getter, icon_url, callback);
+  new WebApkIconHasher(request_context_getter, icon_url, timeout_ms, callback);
 }
 
 WebApkIconHasher::WebApkIconHasher(
     net::URLRequestContextGetter* url_request_context_getter,
     const GURL& icon_url,
+    int timeout_ms,
     const Murmur2HashCallback& callback)
     : callback_(callback) {
   download_timeout_timer_.Start(
-      FROM_HERE,
-      base::TimeDelta::FromMilliseconds(kDownloadTimeoutInMilliseconds),
+      FROM_HERE, base::TimeDelta::FromMilliseconds(timeout_ms),
       base::Bind(&WebApkIconHasher::OnDownloadTimedOut,
                  base::Unretained(this)));
 
   url_fetcher_ = net::URLFetcher::Create(icon_url, net::URLFetcher::GET, this);
   url_fetcher_->SetRequestContext(url_request_context_getter);
   url_fetcher_->Start();
 }
 
 WebApkIconHasher::~WebApkIconHasher() {}
 
@@ skipping 18 matching lines @@
 void WebApkIconHasher::OnDownloadTimedOut() {
   url_fetcher_.reset();
 
   RunCallback("");
 }
 
 void WebApkIconHasher::RunCallback(const std::string& icon_murmur2_hash) {
   callback_.Run(icon_murmur2_hash);
   delete this;
 }