Fix CrOS reverting to Save as PDF and random PDF preview fail

chrome/browser/resources/print_preview/data/app_state.js

Index: chrome/browser/resources/print_preview/data/app_state.js
diff --git a/chrome/browser/resources/print_preview/data/app_state.js b/chrome/browser/resources/print_preview/data/app_state.js
index eeeb2da53b6c52b7054a97b9cda4042d8e9eb394..1554407f13f39d3e277a06d319bad036667e9359 100644
--- a/chrome/browser/resources/print_preview/data/app_state.js
+++ b/chrome/browser/resources/print_preview/data/app_state.js
@@ -138,14 +138,14 @@ cr.define('print_preview', function() {
 
     /** @return {?string} ID of the selected destination. */
     get selectedDestinationId() {

[dpapad, 2016/11/18 00:33:20]

I am also wondering why are all these getters (line 140-187). Can't all callers
use a single getter (selectedDestination at line 193)?

[rbpotter, 2016/11/18 02:59:22]

Done. They were here because they were here before I made this change, so I left
them in and just updated them to work with the new code. Apparently only 2 of
them were ever used...

-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.id : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().id : null;
     },
 
     /** @return {?string} Account the selected destination is registered for. */
     get selectedDestinationAccount() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.account : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().account : null;
     },
 
     /**
@@ -153,28 +153,28 @@ cr.define('print_preview', function() {
      *     selected destination.
      */
     get selectedDestinationOrigin() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.origin : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().origin : null;
     },
 
     /** @return {?print_preview.Cdd} CDD of the selected destination. */
     get selectedDestinationCapabilities() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.capabilities : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().capabilities : null;
     },
 
     /** @return {?string} Name of the selected destination. */
     get selectedDestinationName() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.name : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().name : null;
     },
 
     /**
      * @return {?string} Extension ID associated with the selected destination.
      */
     get selectedDestinationExtensionId() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.extensionId : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().extensionId : null;
     },
 
     /**
@@ -182,8 +182,8 @@ cr.define('print_preview', function() {
      *     destination.
      */
     get selectedDestinationExtensionName() {
-      return this.getSelectedDestination_ ?
-          this.getSelectedDestination_.extensionName : null;
+      return this.getSelectedDestination_() ?
+          this.getSelectedDestination_().extensionName : null;
     },
 
     /**
@@ -191,7 +191,7 @@ cr.define('print_preview', function() {
      *     currently the selected destination.
      */
     get selectedDestination() {
-      return this.getSelectedDestination_;
+      return this.getSelectedDestination_();
     },
 
     /**
@@ -299,7 +299,7 @@ cr.define('print_preview', function() {
      * @param {!print_preview.Destination} dest Destination to persist.
      */
     persistSelectedDestination: function(dest) {
-      if (!this.isInitialized_)
+      if (!this.isInitialized_ || !dest)

[dpapad, 2016/11/18 00:33:20]

Also per the type annotation !print_preview.Destination above, |dest| should
never be null/undefined, so this checks seems odd. Can you either update the
annotation or remove the check if not necessary?

[rbpotter, 2016/11/18 02:59:23]

Removed this and updated the place it was getting called with a null
destination.

         return;
 
       // Determine if this destination is already in the recent destinations,