base::mac::IsOSSierra() -> base::mac::IsOS10_12(), etc.

third_party/WebKit/Source/core/layout/LayoutThemeMac.mm

Index: third_party/WebKit/Source/core/layout/LayoutThemeMac.mm
diff --git a/third_party/WebKit/Source/core/layout/LayoutThemeMac.mm b/third_party/WebKit/Source/core/layout/LayoutThemeMac.mm
index 318293ed309a4c514000cbbf58edc3feefe257f2..d8d2a531de30c4ad100c22393135aa514da8bfc6 100644
--- a/third_party/WebKit/Source/core/layout/LayoutThemeMac.mm
+++ b/third_party/WebKit/Source/core/layout/LayoutThemeMac.mm
@@ -256,7 +256,7 @@ bool LayoutThemeMac::needsHackForTextControlWithFontFamily(const AtomicString& f
 {
     // This hack is only applied on OSX 10.9.
     // https://code.google.com/p/chromium/issues/detail?id=515989#c8
-    return IsOSMavericks() && family == "BlinkMacSystemFont";
+    return IsOS10_9() && family == "BlinkMacSystemFont";
 }
 
 static RGBA32 convertNSColorToColor(NSColor *color)
@@ -478,7 +478,7 @@ bool LayoutThemeMac::isControlStyled(const ComputedStyle& style) const
             return true;
         // NSPopUpButtonCell on macOS 10.9 doesn't support
         // NSUserInterfaceLayoutDirectionRightToLeft.
-        if (IsOSMavericks() && style.direction() == RTL)
+        if (IsOS10_9() && style.direction() == RTL)
             return true;
     }
     // Some other cells don't work well when scaled.