Merge pull request #3920 from brendandahl/text-promise

Use page promise for text extraction.

web/page_view.js

@@ -33,7 +33,6 @@ var PageView = function pageView(container, id, scale,
   this.renderingState = RenderingStates.INITIAL;
   this.resume = null;
 
-  this.textContent = null;
   this.textLayer = null;
 
   this.zoomLayer = null;
@@ -406,10 +405,9 @@ var PageView = function pageView(container, id, scale,
   };
 
   this.getTextContent = function pageviewGetTextContent() {
-    if (!this.textContent) {
+    return PDFView.getPage(this.id).then(function(pdfPage) {
-      this.textContent = this.pdfPage.getTextContent();
+      return pdfPage.getTextContent();
-    }
+    });
-    return this.textContent;
   };
 
   this.draw = function pageviewDraw(callback) {