Fix context menu positioning in MimeHandlerViewGuest.

BUG=422641
Test=Load chrome with the following flags:
--out-of-process-pdf, --enable-mime-handler-view
Load a PDF in a <webview>, e.g. use the webview-sample/browser app:
https://chrome.google.com/webstore/detail/edggnmnajhcbhlnpjnogkjpghaikidaa
and navigate to a PDF.
Right clicking the PDF should bring context menu to correct
position relative to the cursor.

Review URL: https://codereview.chromium.org/667273002

Cr-Commit-Position: refs/heads/master@{#300639}

chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc

@@ -5,8 +5,10 @@
 #include "chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.h"
 
 #include "chrome/browser/chrome_page_zoom.h"
+#include "chrome/browser/renderer_context_menu/render_view_context_menu.h"
 #include "chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h"
 #include "components/pdf/browser/pdf_web_contents_helper.h"
+#include "components/renderer_context_menu/context_menu_delegate.h"
 #include "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.h"
 
 #if defined(ENABLE_PRINTING)
@@ -53,4 +55,17 @@ void ChromeMimeHandlerViewGuestDelegate::ChangeZoom(bool zoom_in) {
       zoom_in ? content::PAGE_ZOOM_IN : content::PAGE_ZOOM_OUT);
 }
 
+bool ChromeMimeHandlerViewGuestDelegate::HandleContextMenu(
+    content::WebContents* web_contents,
+    const content::ContextMenuParams& params) {
+  ContextMenuDelegate* menu_delegate =
+      ContextMenuDelegate::FromWebContents(web_contents);
+  DCHECK(menu_delegate);
+
+  scoped_ptr<RenderViewContextMenu> menu =
+      menu_delegate->BuildMenu(web_contents, params);
+  menu_delegate->ShowMenu(menu.Pass());
+  return true;
+}
+
 }  // namespace extensions

chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.h

@@ -9,6 +9,7 @@
 
 namespace content {
 class WebContents;
+struct ContextMenuParams;
 }  // namespace content
 
 namespace extensions {
@@ -20,6 +21,8 @@ class ChromeMimeHandlerViewGuestDelegate : public MimeHandlerViewGuestDelegate {
 
   // MimeHandlerViewGuestDelegate.
   void AttachHelpers() override;
+  bool HandleContextMenu(content::WebContents* web_contents,
+                         const content::ContextMenuParams& params) override;
   void ChangeZoom(bool zoom_in) override;
 
  private:

extensions/browser/BUILD.gn

@@ -370,6 +370,7 @@ source_set("browser") {
       "guest_view/mime_handler_view/mime_handler_view_constants.h",
       "guest_view/mime_handler_view/mime_handler_view_guest.h",
       "guest_view/mime_handler_view/mime_handler_view_guest.cc",
+      "guest_view/mime_handler_view/mime_handler_view_guest_delegate.cc",
       "guest_view/mime_handler_view/mime_handler_view_guest_delegate.h",
       "guest_view/web_view/javascript_dialog_helper.cc",
       "guest_view/web_view/javascript_dialog_helper.h",

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc

@@ -147,6 +147,14 @@ void MimeHandlerViewGuest::ContentsZoomChange(bool zoom_in) {
     delegate_->ChangeZoom(zoom_in);
 }
 
+bool MimeHandlerViewGuest::HandleContextMenu(
+    const content::ContextMenuParams& params) {
+  if (delegate_)
+    return delegate_->HandleContextMenu(web_contents(), params);
+
+  return false;
+}
+
 void MimeHandlerViewGuest::HandleKeyboardEvent(
     WebContents* source,
     const content::NativeWebKeyboardEvent& event) {

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.h

@@ -10,6 +10,7 @@
 
 namespace content {
 class WebContents;
+struct ContextMenuParams;
 }  // namespace content
 
 namespace extensions {
@@ -47,6 +48,7 @@ class MimeHandlerViewGuest : public GuestView<MimeHandlerViewGuest>,
 
   // WebContentsDelegate implementation.
   void ContentsZoomChange(bool zoom_in) override;
+  bool HandleContextMenu(const content::ContextMenuParams& params) override;
   void HandleKeyboardEvent(
       content::WebContents* source,
       const content::NativeWebKeyboardEvent& event) override;

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.cc

+// Copyright 2014 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 "extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.h"
+
+namespace extensions {
+
+bool MimeHandlerViewGuestDelegate::HandleContextMenu(
+    content::WebContents* web_contents,
+    const content::ContextMenuParams& params) {
+  return false;
+}
+
+}  // namespace extensions

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.h

@@ -9,6 +9,7 @@
 
 namespace content {
 class WebContents;
+struct ContextMenuParams;
 }  // namespace content
 
 namespace extensions {
@@ -24,6 +25,10 @@ class MimeHandlerViewGuestDelegate {
   // Attaches helpers upon initializing the WebContents.
   virtual void AttachHelpers() {}
 
+  // Handles context menu, or returns false if unhandled.
+  virtual bool HandleContextMenu(content::WebContents* web_contents,
+                                 const content::ContextMenuParams& params);
+
   // Request to change the zoom level of the top level page containing
   // this view.
   virtual void ChangeZoom(bool zoom_in) {}

extensions/extensions.gyp

@@ -668,6 +668,7 @@
         'browser/guest_view/guest_view.h',
         'browser/guest_view/mime_handler_view/mime_handler_view_constants.cc',
         'browser/guest_view/mime_handler_view/mime_handler_view_constants.h',
+        'browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.cc',
         'browser/guest_view/mime_handler_view/mime_handler_view_guest_delegate.h',
         'browser/guest_view/mime_handler_view/mime_handler_view_guest.cc',
         'browser/guest_view/mime_handler_view/mime_handler_view_guest.h',