[filebrowser] Introduce View action for supported file types (e.g. pdf).

chrome/browser/resources/file_manager/js/file_manager.js

Index: chrome/browser/resources/file_manager/js/file_manager.js
===================================================================
--- chrome/browser/resources/file_manager/js/file_manager.js	(revision 125140)
+++ chrome/browser/resources/file_manager/js/file_manager.js	(working copy)
@@ -2173,6 +2173,7 @@
   FileManager.prototype.onTasksFound_ = function(selection, tasksList) {
     this.taskItems_.clear();
 
+    var tasksCount = 0;
     for (var i = 0; i < tasksList.length; i++) {
       var task = tasksList[i];
 
@@ -2194,15 +2195,30 @@
         } else if (task_parts[1] == 'gallery') {
           task.iconUrl =
               chrome.extension.getURL('images/icon_preview_16x16.png');
-          task.title = str('GALLERY');
+          task.title = str('OPEN_ACTION');
           task.allTasks = tasksList;
-          this.galleryTask_ = task;
+        } else if (task_parts[1] == 'view-pdf') {
+          // Do not render this task if disabled.
+          if (str('PDF_VIEW_ENABLED') == 'false') continue;
+          task.iconUrl =
+              chrome.extension.getURL('images/icon_preview_16x16.png');
+          task.title = str('OPEN_ACTION');
+        } else if (task_parts[1] == 'view-txt') {
+          task.iconUrl =
+              chrome.extension.getURL('images/icon_preview_16x16.png');
+          task.title = str('OPEN_ACTION');
+        } else if (task_parts[1] == 'install-crx') {
+          // TODO(dgozman): change to the right icon.
+          task.iconUrl =
+              chrome.extension.getURL('images/icon_preview_16x16.png');
+          task.title = str('INSTALL_CRX');
         }
       }
       this.renderTaskItem_(task);
+      tasksCount++;
     }
 
-    this.taskItems_.visible = tasksList.length > 0;
+    this.taskItems_.visible = tasksCount > 0;
 
     selection.tasksList = tasksList;
     if (selection.dispatchDefault) {
@@ -2458,6 +2474,8 @@
         }
       }
       this.openGallery_(urls, noGallery);
+    } else if (id == 'view-pdf' || id == 'view-txt' || id == 'install-crx') {
+      chrome.fileBrowserPrivate.viewFiles(urls, 'default', function() {});
     }
   };