Add static method WebApkIconHasher::DownloadAndComputeMurmur2Hash

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 16 matching lines @@
   // image's raw, unsanitized bytes from the web. |raw_image_data| may contain
   // malicious data. Decoding unsanitized bitmap data to an SkBitmap in the
   // browser process is a security bug.
   uint64_t hash = MurmurHash64A(&raw_image_data.front(), raw_image_data.size(),
                                 kMurmur2HashSeed);
   return base::Uint64ToString(hash);
 }
 
 }  // anonymous namespace
 
+// static
+void WebApkIconHasher::DownloadAndComputeMurmur2Hash(
+    net::URLRequestContextGetter* request_context_getter,
+    const GURL& icon_url,
+    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);
+}
+
 WebApkIconHasher::WebApkIconHasher(
     net::URLRequestContextGetter* url_request_context_getter,
     const GURL& icon_url,
     const Murmur2HashCallback& callback)
-    : url_request_context_getter_(url_request_context_getter),
-      icon_url_(icon_url),
-      callback_(callback) {}
-
-WebApkIconHasher::~WebApkIconHasher() {}
-
-void WebApkIconHasher::DownloadAndComputeMurmur2Hash() {
-  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;
-  }
-
+    : callback_(callback) {
   download_timeout_timer_.Start(
       FROM_HERE,
       base::TimeDelta::FromMilliseconds(kDownloadTimeoutInMilliseconds),
       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_ = net::URLFetcher::Create(icon_url, net::URLFetcher::GET, this);
+  url_fetcher_->SetRequestContext(url_request_context_getter);
   url_fetcher_->Start();
 }
 
+WebApkIconHasher::~WebApkIconHasher() {}
+
 void WebApkIconHasher::OnURLFetchComplete(const net::URLFetcher* source) {
   download_timeout_timer_.Stop();
 
   if (!source->GetStatus().is_success() ||
       source->GetResponseCode() != net::HTTP_OK) {
-    callback_.Run("");
+    RunCallback("");
     return;
   }
 
   // WARNING: We are running in the browser process. |raw_image_data| is the
   // image's raw, unsanitized bytes from the web. |raw_image_data| may contain
   // malicious data. Decoding unsanitized bitmap data to an SkBitmap in the
   // browser process is a security bug.
   std::string raw_image_data;
   source->GetResponseAsString(&raw_image_data);
-  callback_.Run(ComputeMurmur2Hash(raw_image_data));
+  RunCallback(ComputeMurmur2Hash(raw_image_data));
 }
 
 void WebApkIconHasher::OnDownloadTimedOut() {
   url_fetcher_.reset();
 
-  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
-                                                base::Bind(callback_, ""));
+  RunCallback("");
 }
+
+void WebApkIconHasher::RunCallback(const std::string& icon_murmur2_hash) {
+  callback_.Run(icon_murmur2_hash);
+  delete this;
+}