[Translate] Add Variations Headers to the request for the translate script

Bug: 881650
Test: Run chrome with --force-variations-ids=12345, look for the headers in the
request to translate in chrome://net-internals

Change-Id: I51cc33d4d7b0cf9d6a74a433b277f0890b990b01
Reviewed-on: https://chromium-review.googlesource.com/1212403
Commit-Queue: Mathieu Perreault <mathp@chromium.org>
Reviewed-by: Michael Martis <martis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589416}

components/translate/core/browser/BUILD.gn

@@ -59,6 +59,7 @@ static_library("browser") {
     "//components/strings",
     "//components/translate/core/common",
     "//components/variations",
+    "//components/variations/net",
     "//google_apis",
     "//net",
     "//services/metrics/public/cpp:metrics_cpp",

components/translate/core/browser/translate_language_list.cc

@@ -227,8 +227,12 @@ void TranslateLanguageList::RequestLanguageList() {
     NotifyEvent(__LINE__, message);
 
     bool result = language_list_fetcher_->Request(
-        url, base::BindOnce(&TranslateLanguageList::OnLanguageListFetchComplete,
-                            base::Unretained(this)));
+        url,
+        base::BindOnce(&TranslateLanguageList::OnLanguageListFetchComplete,
+                       base::Unretained(this)),
+        // Use the strictest mode for request headers, since incognito state is
+        // not known.
+        /*is_incognito=*/true);
     if (!result)
       NotifyEvent(__LINE__, "Request is omitted due to retry limit");
   }

components/translate/core/browser/translate_manager.cc

@@ -369,7 +369,7 @@ void TranslateManager::TranslatePage(const std::string& original_source_lang,
       base::Bind(&TranslateManager::OnTranslateScriptFetchComplete,
                  GetWeakPtr(), source_lang, target_lang);
 
-  script->Request(callback);
+  script->Request(callback, translate_driver_->IsIncognito());
 }
 
 void TranslateManager::RevertTranslation() {

components/translate/core/browser/translate_script.cc

@@ -59,7 +59,8 @@ TranslateScript::TranslateScript()
 TranslateScript::~TranslateScript() {
 }
 
-void TranslateScript::Request(const RequestCallback& callback) {
+void TranslateScript::Request(const RequestCallback& callback,
+                              bool is_incognito) {
   script_fetch_start_time_ = base::Time::Now().ToJsTime();
 
   DCHECK(data_.empty()) << "Do not fetch the script if it is already fetched";
@@ -73,11 +74,12 @@ void TranslateScript::Request(const RequestCallback& callback) {
 
   GURL translate_script_url = GetTranslateScriptURL();
 
-  fetcher_.reset(new TranslateURLFetcher);
+  fetcher_ = std::make_unique<TranslateURLFetcher>();
   fetcher_->set_extra_request_header(kRequestHeader);
   fetcher_->Request(translate_script_url,
                     base::BindOnce(&TranslateScript::OnScriptFetchComplete,
-                                   base::Unretained(this)));
+                                   base::Unretained(this)),
+                    is_incognito);
 }
 
 // static

components/translate/core/browser/translate_script.h

@@ -43,8 +43,9 @@ class TranslateScript {
   void Clear() { data_.clear(); }
 
   // Fetches the JS translate script (the script that is injected in the page
-  // to translate it).
-  void Request(const RequestCallback& callback);
+  // to translate it). |is_incognito| is used during the fetch to determine
+  // which variations headers to add.
+  void Request(const RequestCallback& callback, bool is_incognito);
 
   // Returns the URL to be used to load the translate script.
   static GURL GetTranslateScriptURL();

components/translate/core/browser/translate_script_unittest.cc

@@ -46,8 +46,9 @@ class TranslateScriptTest : public testing::Test {
   }
 
   void Request() {
-    script_->Request(
-        base::Bind(&TranslateScriptTest::OnComplete, base::Unretained(this)));
+    script_->Request(base::BindRepeating(&TranslateScriptTest::OnComplete,
+                                         base::Unretained(this)),
+                     /*is_incognito=*/false);
   }
 
   const std::string& GetData() { return script_->data(); }

components/translate/core/browser/translate_url_fetcher.cc

@@ -7,6 +7,7 @@
 #include "base/memory/ref_counted.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/translate/core/browser/translate_download_manager.h"
+#include "components/variations/net/variations_http_headers.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_status_code.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
@@ -28,7 +29,8 @@ TranslateURLFetcher::TranslateURLFetcher()
 TranslateURLFetcher::~TranslateURLFetcher() {}
 
 bool TranslateURLFetcher::Request(const GURL& url,
-                                  TranslateURLFetcher::Callback callback) {
+                                  TranslateURLFetcher::Callback callback,
+                                  bool is_incognito) {
   // This function is not supposed to be called if the previous operation is not
   // finished.
   if (state_ == REQUESTING) {
@@ -98,8 +100,12 @@ bool TranslateURLFetcher::Request(const GURL& url,
   if (!extra_request_header_.empty())
     resource_request->headers.AddHeadersFromString(extra_request_header_);
 
-  simple_loader_ = network::SimpleURLLoader::Create(std::move(resource_request),
-                                                    traffic_annotation);
+  simple_loader_ =
+      variations::CreateSimpleURLLoaderWithVariationsHeadersUnknownSignedIn(
+          std::move(resource_request),
+          is_incognito ? variations::InIncognito::kYes
+                       : variations::InIncognito::kNo,
+          traffic_annotation);
   // Set retry parameter for HTTP status code 5xx. This doesn't work against
   // 106 (net::ERR_INTERNET_DISCONNECTED) and so on.
   // TranslateLanguageList handles network status, and implements retry.

components/translate/core/browser/translate_url_fetcher.h

@@ -52,8 +52,9 @@ class TranslateURLFetcher {
   // Requests to |url|. |callback| will be invoked when the function returns
   // true, and the request is finished asynchronously.
   // Returns false if the previous request is not finished, or the request
-  // is omitted due to retry limitation.
-  bool Request(const GURL& url, Callback callback);
+  // is omitted due to retry limitation. |is_incognito| is used during the fetch
+  // to determine which variations headers to add.
+  bool Request(const GURL& url, Callback callback, bool is_incognito);
 
   // Gets internal state.
   State state() { return state_; }