Fix for Multipage selection by dragging mouse in OOP case in PDF.

pdf/pdfium/pdfium_engine.cc

Index: pdf/pdfium/pdfium_engine.cc
diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index c4e703efe65e47a20f9820b1c788d4c4add59681..5a7bdb8bc051c8e25ad1a3cd1b2eafc3ad5dce31 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1730,7 +1730,7 @@ bool PDFiumEngine::OnMouseDown(const pp::MouseInputEvent& event) {
 }
 
 void PDFiumEngine::OnSingleClick(int page_index, int char_index) {
-  selecting_ = true;
+  SetSelecting(true);
   selection_.push_back(PDFiumRange(pages_[page_index], char_index, 0));
 }
 
@@ -1793,7 +1793,7 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
   if (!selecting_)
     return false;
 
-  selecting_ = false;
+  SetSelecting(false);
   return true;
 }
 
@@ -3469,6 +3469,13 @@ void PDFiumEngine::RotateInternal() {
   }
 }
 
+void PDFiumEngine::SetSelecting(bool selecting) {
+  bool was_selecting = selecting_;
+  selecting_ = selecting;
+  if (selecting_ != was_selecting)
+    client_->IsSelectingChanged(selecting);
+}
+
 void PDFiumEngine::Form_Invalidate(FPDF_FORMFILLINFO* param,
                                    FPDF_PAGE page,
                                    double left,