Fix variation id transmission with feedback reports.

This was originally added by this CL:
https://chromiumcodereview.appspot.com/15714003

But later broke when the code was componentized here:
https://codereview.chromium.org/116863002

This CL restores the original functionality and adds
a test to hopefully prevent it from regressing in the
future.

BUG=460604

Review URL: https://codereview.chromium.org/942863003

Cr-Commit-Position: refs/heads/master@{#317655}

components/components_tests.gyp

@@ -166,6 +166,7 @@
             'enhanced_bookmarks/item_position_unittest.cc',
             'feedback/feedback_common_unittest.cc',
             'feedback/feedback_data_unittest.cc',
+            'feedback/feedback_uploader_chrome_unittest.cc',
             'feedback/feedback_uploader_unittest.cc',
             'gcm_driver/gcm_account_mapper_unittest.cc',
             'gcm_driver/gcm_channel_status_request_unittest.cc',
@@ -640,6 +641,7 @@
               'sources!': [
                 'feedback/feedback_common_unittest.cc',
                 'feedback/feedback_data_unittest.cc',
+                'feedback/feedback_uploader_chrome_unittest.cc',
                 'feedback/feedback_uploader_unittest.cc',
                 'gcm_driver/gcm_account_mapper_unittest.cc',
                 'gcm_driver/gcm_channel_status_request_unittest.cc',

components/feedback.gypi

@@ -14,6 +14,7 @@
         '../third_party/zlib/google/zip.gyp:zip',
         'keyed_service_core',
         'feedback_proto',
+        'components.gyp:variations_http_provider',
       ],
       'include_dirs': [
         '..',

components/feedback/BUILD.gn

@@ -30,6 +30,7 @@ static_library("feedback") {
     "//base",
     "//components/keyed_service/core:core",
     "//components/feedback/proto",
+    "//components/variations/net",
     "//content/public/common",
     "//net",
     "//third_party/zlib:zip",

components/feedback/DEPS

@@ -2,6 +2,7 @@ include_rules = [
   "-content",
   "+components/keyed_service",
   "+components/user_prefs",
+  "+components/variations",
   "+content/public/browser",
   "+content/public/test",
   "+net/base",

components/feedback/feedback_uploader_chrome.cc

@@ -4,6 +4,8 @@
 
 #include "components/feedback/feedback_uploader_chrome.h"
 
+#include <string>
+
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ -12,6 +14,7 @@
 #include "components/feedback/feedback_report.h"
 #include "components/feedback/feedback_switches.h"
 #include "components/feedback/feedback_uploader_delegate.h"
+#include "components/variations/net/variations_http_header_provider.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/load_flags.h"
@@ -42,14 +45,21 @@ FeedbackUploaderChrome::FeedbackUploaderChrome(
 void FeedbackUploaderChrome::DispatchReport(const std::string& data) {
   GURL post_url(url_);
 
+  // Note: FeedbackUploaderDelegate deletes itself and the fetcher.
   net::URLFetcher* fetcher = net::URLFetcher::Create(
       post_url, net::URLFetcher::POST,
       new FeedbackUploaderDelegate(
           data,
           base::Bind(&FeedbackUploaderChrome::UpdateUploadTimer, AsWeakPtr()),
           base::Bind(&FeedbackUploaderChrome::RetryReport, AsWeakPtr())));
 
-  fetcher->SetUploadData(std::string(kProtoBufMimeType), data);
+  // Tell feedback server about the variation state of this install.
+  net::HttpRequestHeaders headers;
+  variations::VariationsHttpHeaderProvider::GetInstance()->AppendHeaders(
+      fetcher->GetOriginalURL(), context_->IsOffTheRecord(), false, &headers);
+  fetcher->SetExtraRequestHeaders(headers.ToString());
+
+  fetcher->SetUploadData(kProtoBufMimeType, data);
   fetcher->SetRequestContext(context_->GetRequestContext());
   fetcher->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                         net::LOAD_DO_NOT_SEND_COOKIES);

components/feedback/feedback_uploader_chrome_unittest.cc

@@ -0,0 +1,65 @@
+// Copyright 2015 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 "components/feedback/feedback_uploader_chrome.h"
+
+#include "base/message_loop/message_loop.h"
+#include "base/metrics/field_trial.h"
+#include "components/variations/variations_associated_data.h"
+#include "content/public/test/test_browser_context.h"
+#include "net/url_request/test_url_fetcher_factory.h"
+#include "net/url_request/url_fetcher_delegate.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace feedback {
+
+class FeedbackUploaderChromeTest : public ::testing::Test {
+ protected:
+  FeedbackUploaderChromeTest() {}
+
+  ~FeedbackUploaderChromeTest() override {
+    // Clean up registered ids.
+    variations::testing::ClearAllVariationIDs();
+  }
+
+  // Registers a field trial with the specified name and group and an associated
+  // google web property variation id.
+  void CreateFieldTrialWithId(const std::string& trial_name,
+                              const std::string& group_name,
+                              int variation_id) {
+    variations::AssociateGoogleVariationID(
+        variations::GOOGLE_WEB_PROPERTIES, trial_name, group_name,
+        static_cast<variations::VariationID>(variation_id));
+    base::FieldTrialList::CreateFieldTrial(trial_name, group_name)->group();
+  }
+
+ private:
+  base::MessageLoopForUI message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(FeedbackUploaderChromeTest);
+};
+
+TEST_F(FeedbackUploaderChromeTest, VariationHeaders) {
+  // Register a trial and variation id, so that there is data in variations
+  // headers.
+  base::FieldTrialList field_trial_list_(NULL);
+  CreateFieldTrialWithId("Test", "Group1", 123);
+
+  content::TestBrowserContext context;
+  FeedbackUploaderChrome uploader(&context);
+
+  net::TestURLFetcherFactory factory;
+  uploader.DispatchReport("test");
+
+  net::TestURLFetcher* fetcher = factory.GetFetcherByID(0);
+  net::HttpRequestHeaders headers;
+  fetcher->GetExtraRequestHeaders(&headers);
+  std::string value;
+  EXPECT_TRUE(headers.GetHeader("X-Client-Data", &value));
+  EXPECT_FALSE(value.empty());
+  // The fetcher's delegate is responsible for freeing the fetcher (and itself).
+  fetcher->delegate()->OnURLFetchComplete(fetcher);
+}
+
+}  // namespace feedback