Fix for PDFs with lots of named destinations take a long time to load.

chrome/browser/resources/pdf/pdf.js

Index: chrome/browser/resources/pdf/pdf.js
diff --git a/chrome/browser/resources/pdf/pdf.js b/chrome/browser/resources/pdf/pdf.js
index 309886fde637a343d583d44f3d367064a374c317..5c41ea7f984b20785980095a3930f7afc46803c1 100644
--- a/chrome/browser/resources/pdf/pdf.js
+++ b/chrome/browser/resources/pdf/pdf.js
@@ -190,10 +190,11 @@ function PDFViewer(streamDetails) {
   }
 
   // Parse open pdf parameters.
-  this.paramsParser_ = new OpenPDFParamsParser();
+  this.paramsParser_ =
+      new OpenPDFParamsParser(this.getNamedDestination_.bind(this));

[raymes, 2015/02/16 02:02:31]

There is some refactoring that would be really nice to do here, but let's leave
it for another CL if you are interested. The idea is to create a PluginProxy
class for communicating with the plugin. Rather than passing in
this.getNamedDestination_ here, we would pass in the PluginProxy class which has
a function getNamedDestination hanging off it.

[Deepak, 2015/02/16 06:45:38]

I agree with you, will do it in-separate CL.
Thanks

   this.navigator_ = new Navigator(this.streamDetails_.originalUrl,
-      this.viewport_, this.paramsParser_, onNavigateInCurrentTab,
-      onNavigateInNewTab);
+                                  this.viewport_, this.paramsParser_,
+                                  onNavigateInCurrentTab, onNavigateInNewTab);
   this.viewportScroller_ =
       new ViewportScroller(this.viewport_, this.plugin_, window);
 }
@@ -350,13 +351,32 @@ PDFViewer.prototype = {
    * @private
    * Notify the plugin to print.
    */
-  print_: function() { this.plugin_.postMessage({type: 'print'}); },
+  print_: function() {
+    this.plugin_.postMessage({
+      type: 'print'
+    });
+  },
 
   /**
    * @private
    * Notify the plugin to save.
    */
-  save_: function() { this.plugin_.postMessage({type: 'save'}); },
+  save_: function() {
+    this.plugin_.postMessage({
+      type: 'save'
+    });
+  },
+
+  /**
+   * Callback to fetch namedDestination from plugin.

[raymes, 2015/02/16 02:02:31]

nit: Fetches the page number corresponding to the given named destination from
the plugin. 

[Deepak, 2015/02/16 06:45:38]

Done.

+   * @param {string} name The namedDestination to fetch page number from plugin.
+   */
+  getNamedDestination_: function(name) {
+    this.plugin_.postMessage({
+      type: 'getNamedDestination',
+      namedDestination: name
+    });
+  },
 
   /**
    * @private
@@ -365,20 +385,20 @@ PDFViewer.prototype = {
    * important as later actions can override the effects of previous actions.
    */
   handleURLParams_: function() {
-    var urlParams =
-        this.paramsParser_.getViewportFromUrlParams(
-            this.streamDetails_.originalUrl);
-    if (urlParams.page)
-      this.viewport_.goToPage(urlParams.page);
-    if (urlParams.position) {
-      // Make sure we don't cancel effect of page parameter.
-      this.viewport_.position = {
-        x: this.viewport_.position.x + urlParams.position.x,
-        y: this.viewport_.position.y + urlParams.position.y
-      };
-    }
-    if (urlParams.zoom)
-      this.viewport_.setZoom(urlParams.zoom);
+    this.paramsParser_.getViewportFromUrlParams(
+        this.streamDetails_.originalUrl, function(initialViewport) {

[raymes, 2015/02/16 02:02:31]

nit: viewportPosition

[Deepak, 2015/02/16 06:45:38]

Done.

+          if (initialViewport.page != undefined)
+            this.viewport_.goToPage(initialViewport.page);
+          if (initialViewport.position) {
+            // Make sure we don't cancel effect of page parameter.
+            this.viewport_.position = {
+              x: this.viewport_.position.x + initialViewport.position.x,
+              y: this.viewport_.position.y + initialViewport.position.y
+            };
+          }
+          if (initialViewport.zoom)
+            this.viewport_.setZoom(initialViewport.zoom);
+        }.bind(this));
   },
 
   /**
@@ -486,9 +506,6 @@ PDFViewer.prototype = {
         else
           this.navigator_.navigate(message.data.url, message.data.newTab);
         break;
-      case 'setNamedDestinations':
-        this.paramsParser_.namedDestinations = message.data.namedDestinations;
-        break;
       case 'setScrollPosition':
         var position = this.viewport_.position;
         if (message.data.x !== undefined)
@@ -519,6 +536,10 @@ PDFViewer.prototype = {
       case 'setIsSelecting':
         this.viewportScroller_.setEnableScrolling(message.data.isSelecting);
         break;
+      case 'getNamedDestinationReply':
+        this.paramsParser_.onNamedDestinationReceived(
+            message.data.namedDestinationPageNumber);
+        break;
     }
   },