Switch to LayoutThemeMobile when emulating mobile device in DevTools.

third_party/WebKit/Source/core/layout/LayoutTheme.cpp

 /**
  * This file is part of the theme implementation for form controls in WebCore.
  *
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 24 matching lines @@
 #include "core/html/HTMLDataListOptionsCollection.h"
 #include "core/html/HTMLFormControlElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLMeterElement.h"
 #include "core/html/HTMLOptionElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/html/shadow/MediaControlElements.h"
 #include "core/html/shadow/ShadowElementNames.h"
 #include "core/html/shadow/SpinButtonElement.h"
 #include "core/html/shadow/TextControlInnerElements.h"
+#include "core/layout/LayoutThemeMobile.h"
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "core/style/ComputedStyle.h"
 #include "platform/FileMetadata.h"
 #include "platform/FloatConversion.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/fonts/FontSelector.h"
 #include "platform/text/PlatformLocale.h"
 #include "platform/text/StringTruncator.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebFallbackThemeEngine.h"
 #include "public/platform/WebRect.h"
 #include "wtf/text/StringBuilder.h"
 
 #if USE(NEW_THEME)
 #include "platform/Theme.h"
 #endif
 
 // The methods in this file are shared by all themes on every platform.
 
 namespace blink {
 
 using namespace HTMLNames;
 
+LayoutTheme& LayoutTheme::theme()
+{
+    if (RuntimeEnabledFeatures::mobileLayoutThemeEnabled()) {
+        DEFINE_STATIC_REF(LayoutTheme, layoutThemeMobile, (LayoutThemeMobile::create()));

[dgozman, 2016/02/11 18:53:44]

This is the meaningful part of the patch.

[pdr., 2016/02/12 06:36:14]

This seems incorrect anytime we share a render process. For example, if the user
is emulating android on windows and opens a new tab, the new tab can have the
android theme.

I made a testcase for this bug, just emulate and click the link:
http://jsbin.com/nupahu

[dgozman, 2016/02/19 19:15:16]

I'm aware of this problem, but redesigning away from statics is too big an
effort not worth it for such a small difference in emulation. We do not pretend
to be 100% equal to android anyway.
Similar story happens with overlay scrollbars, which we switch on per-process
basis.

+        return *layoutThemeMobile;
+    }
+    return nativeTheme();
+}
+
 LayoutTheme::LayoutTheme()
     : m_hasCustomFocusRingColor(false)
 #if USE(NEW_THEME)
     , m_platformTheme(platformTheme())
 #endif
 {
 }
 
 void LayoutTheme::adjustStyle(ComputedStyle& style, Element* e)
 {
@@ skipping 858 matching lines @@
 
     // padding - not honored by WinIE, needs to be removed.
     style.resetPadding();
 
     // border - honored by WinIE, but looks terrible (just paints in the control box and turns off the Windows XP theme)
     // for now, we will not honor it.
     style.resetBorder();
 }
 
 } // namespace blink