Switch to LayoutThemeMobile when emulating mobile device in DevTools.

third_party/WebKit/Source/core/layout/LayoutThemeDefault.h

Index: third_party/WebKit/Source/core/layout/LayoutThemeDefault.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutThemeDefault.h b/third_party/WebKit/Source/core/layout/LayoutThemeDefault.h
index bb728751892e5dcbf6b5e2c9284d8feda4bc72f5..f7c4bb5921fa660f68c65f7905693373caa9c14d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutThemeDefault.h
+++ b/third_party/WebKit/Source/core/layout/LayoutThemeDefault.h
@@ -63,9 +63,12 @@ public:
 
     static void setCaretBlinkInterval(double);
 
+#if !USE(NEW_THEME)

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

These theme checks are tricky. WDYT about a pixel test to make sure all the
platforms look the same when emulation is enabled? For example, a page that has
all the controls on it and emulation enabled.

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

I've reworked this to remove all NEW_THEME checks (and the flag altogether). Now
there should be no concern about differences as the code is exactly the same.
I'd prefer to not add an emulation pixel test which will need
attention/rebaselines from anyone working on layout theme. I think there would
be failures and we'll end up disabling it.

     void setCheckboxSize(ComputedStyle&) const override;
     void setRadioSize(ComputedStyle&) const override;
     void adjustInnerSpinButtonStyle(ComputedStyle&) const override;
+    void adjustButtonStyle(ComputedStyle&) const override;
+#endif
 
     bool popsMenuBySpaceKey() const final { return true; }
     bool popsMenuByReturnKey() const final { return true; }
@@ -91,7 +94,6 @@ public:
 
     int minimumMenuListSize(const ComputedStyle&) const override;
 
-    void adjustButtonStyle(ComputedStyle&) const override;
     void adjustSearchFieldStyle(ComputedStyle&) const override;
     void adjustSearchFieldCancelButtonStyle(ComputedStyle&) const override;
     void adjustSearchFieldDecorationStyle(ComputedStyle&) const override;