Print Preview: Making margin selection sticky (part 2/2)

chrome/browser/resources/print_preview/print_preview.js

Index: chrome/browser/resources/print_preview/print_preview.js
diff --git a/chrome/browser/resources/print_preview/print_preview.js b/chrome/browser/resources/print_preview/print_preview.js
index 04ffee4529118a18fcfe7092d53e3c59cca8957e..1886ea30f27c79a9d61b781206f2b92cb3f124e0 100644
--- a/chrome/browser/resources/print_preview/print_preview.js
+++ b/chrome/browser/resources/print_preview/print_preview.js
@@ -163,9 +163,50 @@ function onLoad() {
   $('printer-list').onchange = updateControlsWithSelectedPrinterCapabilities;
 
   previewArea.showLoadingAnimation();
-  chrome.send('getInitiatorTabTitle');
-  chrome.send('getDefaultPrinter');
-  chrome.send('getNumberFormatAndMeasurementSystem');
+  serializeRequests();
+  chrome.send('getInitialSettings');
+}
+
+/**
+ * Serializes requests |getNumberFormatAndMeasurementSystem|,
+ * |getLastUsedMarginSettings| and |getDefaultPrinter|. It guarantees that
+ * responses to those requests will arrive in the order requested.
+ */
+function serializeRequests() {
+  var oldSetInitialSettings = setInitialSettings;
+  setInitialSettings = function setInitialSettings(initiatorTabTitle,
+      numberFormat, measurementSystem, lastUsedMarginType,
+      lastUsedCustomMargins, isModifiable) {
+    oldSetInitialSettings(initiatorTabTitle, numberFormat, measurementSystem,
+      lastUsedMarginType, lastUsedCustomMargins, isModifiable);
+    chrome.send('getDefaultPrinter');
+  };
+}
+
+/**
+ * @param {string} initiatorTabTitle The title of the initiator tab.
+ * @param {string} numberFormat Look at
+ *     |MarginSettings.setNumberFormatAndMeasurementSystem| for documentation.
+ * @param {numner} measurementSystem Look at
+ *     |MarginSettings.setNumberFormatAndMeasurementSystem| for documentation.
+ * @param {number} lastUsedMarginType Look at
+ *     |MarginSettings.setLastUsedMargins| for documentation.
+ * @param {object} lastUsedCustomMargins Look at
+ *     |MarginSettings.setLastUsedMargins| for documentation.
+ * @param {boolean} isModifiable Indicates whether the previewed document
+ *      can be modified.
+ */
+function setInitialSettings(initiatorTabTitle, numberFormat, measurementSystem,
+                            lastUsedMarginType, lastUsedCustomMargins,
+                            isModifiable) {
+  setInitiatorTabTitle(initiatorTabTitle);
+  previewModifiable = isModifiable;
+  if (previewModifiable) {
+    print_preview.MarginSettings.setNumberFormatAndMeasurementSystem(
+        numberFormat, measurementSystem);
+    marginSettings.setLastUsedMargins(lastUsedMarginType,
+                                      lastUsedCustomMargins);
+  }
 }
 
 /**
@@ -283,7 +324,7 @@ function updateControlsWithSelectedPrinterCapabilities() {
     lastSelectedPrinterIndex = selectedIndex;
 
     // Regenerate the preview data based on selected printer settings.
-    setDefaultValuesAndRegeneratePreview(true);
+    setDefaultValuesAndRegeneratePreview(false);
   }
 }
 
@@ -303,7 +344,7 @@ function doUpdateCloudPrinterCapabilities(printer) {
   lastSelectedPrinterIndex = selectedIndex;
 
   // Regenerate the preview data based on selected printer settings.
-  setDefaultValuesAndRegeneratePreview(true);
+  setDefaultValuesAndRegeneratePreview(false);
 }
 
 /**
@@ -577,12 +618,8 @@ function fileSelectionCompleted() {
  * @param {string} printer Name of the default printer. Empty if none.
  * @param {string} cloudPrintData Cloud print related data to restore if
  *     the default printer is a cloud printer.
- * @param {number} lastUsedMarginsType Indicates the last used margins type
- *     (matches enum MarginType in printing/print_job_constants.h.
  */
-function setDefaultPrinter(printer_name, cloudPrintData, lastUsedMarginsType) {
-  // Setting the margin selection to the last used one.
-  marginSettings.setLastUsedMarginsType(lastUsedMarginsType);
+function setDefaultPrinter(printer_name, cloudPrintData) {
   // Add a placeholder value so the printer list looks valid.
   addDestinationListOption('', '', true, true, true);
   if (printer_name) {
@@ -778,16 +815,13 @@ function setPluginPreviewPageCount() {
  * Update the page count and check the page range.
  * Called from PrintPreviewUI::OnDidGetPreviewPageCount().
  * @param {number} pageCount The number of pages.
- * @param {boolean} isModifiable Indicates whether the previewed document can be
- *     modified.
  * @param {number} previewResponseId The preview request id that resulted in
  *     this response.
  */
-function onDidGetPreviewPageCount(pageCount, isModifiable, previewResponseId) {
+function onDidGetPreviewPageCount(pageCount, previewResponseId) {
   if (!isExpectedPreviewResponse(previewResponseId))
     return;
   pageSettings.updateState(pageCount);
-  previewModifiable = isModifiable;
   if (!previewModifiable && pageSettings.requestPrintPreviewIfNeeded())
     return;
 
@@ -1057,8 +1091,6 @@ PrintSettings.prototype.save = function() {
 
 /**
  * Updates the title of the print preview tab according to |initiatorTabTitle|.
- * Called from PrintPreviewUI::OnGetInitiatorTabTitle as a result of sending a
- * 'getInitiatorTabTitle' message.
  * @param {string} initiatorTabTitle The title of the initiator tab.
  */
 function setInitiatorTabTitle(initiatorTabTitle) {