Support device scale factor test with popups in LayoutTest

content/shell/browser/shell.cc

Index: content/shell/browser/shell.cc
diff --git a/content/shell/browser/shell.cc b/content/shell/browser/shell.cc
index 12fde0b981f9818af5e2e58520567335a75aaf31..de632720474d515549a59a47d3108707c486f457 100644
--- a/content/shell/browser/shell.cc
+++ b/content/shell/browser/shell.cc
@@ -18,6 +18,7 @@
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host.h"
+#include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/content_switches.h"
@@ -34,6 +35,12 @@
 #include "content/shell/browser/shell_javascript_dialog_manager.h"
 #include "content/shell/common/shell_messages.h"
 #include "content/shell/common/shell_switches.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/switches.h"
+
+#if defined(USE_X11) && !defined(OS_CHROMEOS)
+#include "ui/views/widget/desktop_aura/desktop_screen_x11.h"
+#endif
 
 namespace content {
 
@@ -383,6 +390,19 @@ bool Shell::HandleContextMenu(const content::ContextMenuParams& params) {
   return PlatformHandleContextMenu(params);
 }
 
+void Shell::SetDeviceScaleFactor(float scale) {
+#if !defined(OS_CHROMEOS)
+  gfx::Display::ResetForceDeviceScaleFactorForTesting();
+  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+      switches::kForceDeviceScaleFactor, base::StringPrintf("%f", scale));
+#if defined(USE_X11)
+  views::DesktopScreenX11::UpdateDeviceScaleFactorForTest();
+#endif
+#endif
+  RenderWidgetHostView* host_view = web_contents_->GetRenderWidgetHostView();
+  host_view->SetSize(host_view->GetViewBounds().size());
+}
+
 gfx::Size Shell::GetShellDefaultSize() {
   static gfx::Size default_shell_size;
   if (!default_shell_size.IsEmpty())