replaced download icon for the sprite based one

app/assets/javascripts/pipelines/components/pipelines_artifacts.vue

 <script>
   import tooltip from '../../vue_shared/directives/tooltip';
+  import Icon from '../../vue_shared/components/icon.vue';
   export default {
     props: {
@@ -11,6 +12,9 @@
     directives: {
       tooltip,
     },
+    components: {
+      Icon,
+    },
   };
 </script>
 <template>
@@ -24,10 +28,9 @@
       data-placement="top"
       data-toggle="dropdown"
       aria-label="Artifacts">
-      <i
-        class="fa fa-download"
-        aria-hidden="true">
-      </i>
+      <icon 
+        name="download">
+      </icon>
       <i
         class="fa fa-caret-down"
         aria-hidden="true">

app/assets/javascripts/vue_merge_request_widget/components/mr_widget_header.js

 import tooltip from '../../vue_shared/directives/tooltip';
 import { pluralize } from '../../lib/utils/text_utility';
+import { spriteIcon } from '../../lib/utils/common_utils';
 export default {
   name: 'MRWidgetHeader',
@@ -25,6 +26,9 @@ export default {
         gfm: `\`${this.mr.sourceBranch}\``,
       });
     },
+    downloadIcon() {
+      return spriteIcon('download');
+    },
   },
   methods: {
     isBranchTitleLong(branchTitle) {
@@ -82,8 +86,7 @@ export default {
             aria-label="Download as"
             role="button">
             <i
-              class="fa fa-download"
-              aria-hidden="true">
+              v-html="downloadIcon">
             </i>
             <i
               class="fa fa-caret-down"

app/helpers/blob_helper.rb

@@ -232,7 +232,7 @@ module BlobHelper
     return if blob.empty?
     if blob.raw_binary? || blob.stored_externally?
-      icon = icon('download')
+      icon = sprite_icon('download')
       title = 'Download'
     else
       icon = icon('file-code-o')

app/views/projects/artifacts/browse.html.haml

@@ -18,7 +18,7 @@
     .tree-controls
       = link_to download_project_job_artifacts_path(@project, @build),
         rel: 'nofollow', download: '', class: 'btn btn-default download' do
-        = icon('download')
+        = sprite_icon('download')
         Download artifacts archive
   .tree-content-holder

app/views/projects/blob/viewers/_download.html.haml

@@ -2,6 +2,6 @@
   .center.render-error.vertical-center
     = link_to blob_raw_path do
       %h1.light
-        = icon('download')
+        = sprite_icon('download')
       %h4
         Download (#{number_to_human_size(viewer.blob.raw_size)})

app/views/projects/buttons/_download.html.haml

@@ -3,7 +3,7 @@
 - if !project.empty_repo? && can?(current_user, :download_code, project)
   .project-action-button.dropdown.inline>
     %button.btn.has-tooltip{ title: s_('DownloadSource|Download'), 'data-toggle' => 'dropdown', 'aria-label' => s_('DownloadSource|Download') }
-      = icon('download')
+      = sprite_icon('download')
       = icon("caret-down")
       %span.sr-only=  _('Select Archive Format')
     %ul.dropdown-menu.dropdown-menu-align-right{ role: 'menu' }

app/views/projects/ci/builds/_build.html.haml

@@ -96,7 +96,7 @@
     .pull-right
       - if can?(current_user, :read_build, job) && job.artifacts?
         = link_to download_project_job_artifacts_path(job.project, job), rel: 'nofollow', download: '', title: 'Download artifacts', class: 'btn btn-build' do
-          = icon('download')
+          = sprite_icon('download')
       - if can?(current_user, :update_build, job)
         - if job.active?
           = link_to cancel_project_job_path(job.project, job, return_to: request.original_url), method: :post, title: 'Cancel', class: 'btn btn-build' do