PDF Viewer - Show context menu for links on right click

Currently context menu for page is shown when right clicked
on links in the pdf. This happens because an empty string is
returned as url to ContextMenuClientImpl::showContextMenu()
from plugin.

The reason for above is that GetLinkAtPosition() isn't passing
a point in page coordinates to GetCharIndex() and GetCharIndex()
expects the point to be in page coordinate. This means that when
the document is zoomed or scrolled and right click is done then
it doesn't work.

This patch updates the point passed to GetCharIndex() to be in
page coordinates by factoring in current position and zoom level.

BUG=148665

Review URL: https://codereview.chromium.org/553453002

Cr-Commit-Position: refs/heads/master@{#294256}

1 files changed, 4 insertions, 1 deletions

diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index e6713271..f0fe1b2 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1867,7 +1867,10 @@ std::string PDFiumEngine::GetSelectedText() {
 std::string PDFiumEngine::GetLinkAtPosition(const pp::Point& point) {
   int temp;
   PDFiumPage::LinkTarget target;
-  PDFiumPage::Area area = GetCharIndex(point, &temp, &temp, &target);
+  pp::Point point_in_page(
+      static_cast<int>((point.x() + position_.x()) / current_zoom_),
+      static_cast<int>((point.y() + position_.y()) / current_zoom_));
+  PDFiumPage::Area area = GetCharIndex(point_in_page, &temp, &temp, &target);
   if (area == PDFiumPage::WEBLINK_AREA)
     return target.url;
   return std::string();