Remove ThemeColor runtime feature

According to Bug 383941, this feature has been stable since mid July.

BUG=402536

Review URL: https://codereview.chromium.org/684913002

git-svn-id: svn://svn.chromium.org/blink/trunk@184902 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/Document.cpp

@@ -4716,9 +4716,6 @@ Vector<IconURL> Document::iconURLs(int iconTypesMask)
 
 Color Document::themeColor() const
 {
-    if (!RuntimeEnabledFeatures::themeColorEnabled())
-        return Color();
-
     for (HTMLMetaElement* metaElement = head() ? Traversal<HTMLMetaElement>::firstChild(*head()) : 0; metaElement; metaElement = Traversal<HTMLMetaElement>::nextSibling(*metaElement)) {
         RGBA32 rgb = Color::transparent;
         if (equalIgnoringCase(metaElement->name(), "theme-color") && CSSParser::parseColor(rgb, metaElement->content().string().stripWhiteSpace(), true))

third_party/WebKit/Source/core/html/HTMLMetaElement-in.cpp

@@ -472,7 +472,7 @@ void HTMLMetaElement::process()
             processViewportContentAttribute("width=device-width", ViewportDescription::HandheldFriendlyMeta);
         else if (equalIgnoringCase(nameValue, "mobileoptimized"))
             processViewportContentAttribute("width=device-width, initial-scale=1", ViewportDescription::MobileOptimizedMeta);
-        else if (RuntimeEnabledFeatures::themeColorEnabled() && equalIgnoringCase(nameValue, "theme-color") && document().frame())
+        else if (equalIgnoringCase(nameValue, "theme-color") && document().frame())
             document().frame()->loader().client()->dispatchDidChangeThemeColor();
     }
 

third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in

@@ -126,7 +126,6 @@ Stream status=experimental
 SubpixelFontScaling status=stable
 SubresourceIntegrity status=experimental
 TextBlob
-ThemeColor status=stable
 ThreadedParserDataReceiver status=experimental
 // Many websites disable mouse support when touch APIs are available.  We'd
 // like to enable this always but can't until more websites fix this bug.