GuestView: Move Disable Drag and Drop Out to Chrome

chrome/browser/guest_view/guest_view_base.cc

Index: chrome/browser/guest_view/guest_view_base.cc
diff --git a/chrome/browser/guest_view/guest_view_base.cc b/chrome/browser/guest_view/guest_view_base.cc
index 122833cd63eb067971eea24bf36f2e5e4e29af2c..884903de9223f399cb4db5493d9422455d8317f9 100644
--- a/chrome/browser/guest_view/guest_view_base.cc
+++ b/chrome/browser/guest_view/guest_view_base.cc
@@ -5,13 +5,16 @@
 #include "chrome/browser/guest_view/guest_view_base.h"
 
 #include "base/lazy_instance.h"
+#include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/guest_view/ad_view/ad_view_guest.h"
 #include "chrome/browser/guest_view/guest_view_constants.h"
 #include "chrome/browser/guest_view/guest_view_manager.h"
 #include "chrome/browser/guest_view/web_view/web_view_guest.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/content_settings.h"
+#include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/browser/event_router.h"
@@ -223,6 +226,16 @@ void GuestViewBase::RegisterDestructionCallback(
   destruction_callback_ = callback;
 }
 
+void GuestViewBase::DidStopLoading(content::RenderViewHost* render_view_host) {
+  // Disable drag-and-drop by default. Derived classes that override this method

[lazyboy, 2014/05/30 00:30:52]

Don't think this is a good way of doing this: "you need to override
DidStopLoading to disable drag and drop"
Also this changes behavior: Every guest view to have dnd enabled instead of just
WebViewGuest.

I think we should add a GuestViewBase::IsDNDEnabled() and check that before
running this script. It's cleaner to understand what's going on that way.

[Fady Samuel, 2014/05/30 01:53:21]

You got the logic reversed. This disables DND by default. Overriding this method
enables it. 

[lazyboy, 2014/05/30 03:11:40]

Yeah I misread.
But my concern is still the same, I'm not concerned about dnd being enabled or
disabled by default; Overriding DidStopLoad magically changing the behavior of
enable/disable dnd would seem very surprising to a Derived class imo.
e.g. XViewGuest gets dnd disabled by default but if they want to do sth on
loadstop and and later override DidStopLoading then dnd gets enabled which
doesn't seem intuitive.

+  // can avoid the script injection, thereby enabling drag-and-drop.
+  const char script[] = "window.addEventListener('dragstart', function() { "
+                        "  window.event.preventDefault(); "
+                        "});";
+  render_view_host->GetMainFrame()->ExecuteJavaScript(
+      base::ASCIIToUTF16(script));
+}
+
 void GuestViewBase::WebContentsDestroyed() {
   delete this;
 }