Add ability to select all using keyboard (Ctrl+A) in PDF forms.

pdf/pdfium/pdfium_engine.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "pdf/pdfium/pdfium_engine.h"
 
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 2417 matching lines @@
     case PERMISSION_PRINT_HIGH_QUALITY:
       // With security handler revision 2 rules, check the same bit for high
       // and low quality. See table 3.20 in the PDF 1.7 spec.
       return (permissions_ & kPDFPermissionPrintLowQualityMask) != 0;
     default:
       return true;
   }
 }
 
 void PDFiumEngine::SelectAll() {
+  if (in_form_text_area_)
+    return;
+
   SelectionChangeInvalidator selection_invalidator(this);
 
   selection_.clear();
   for (const auto& page : pages_) {
     if (page->available())
       selection_.push_back(PDFiumRange(page.get(), 0, page->GetCharCount()));
   }
 }
 
 int PDFiumEngine::GetNumberOfPages() {
@@ skipping 1760 matching lines @@
   FPDF_DOCUMENT doc =
       FPDF_LoadMemDocument(pdf_buffer, pdf_buffer_size, nullptr);
   if (!doc)
     return false;
   bool success = FPDF_GetPageSizeByIndex(doc, page_number, width, height) != 0;
   FPDF_CloseDocument(doc);
   return success;
 }
 
 }  // namespace chrome_pdf