Remove unused WebRuntimeFeatures::enableStableFeatures

As of chromium r254438 this method is never called.

[1] https://src.chromium.org/viewvc/chrome?view=rev&revision=254438

Review URL: https://codereview.chromium.org/205733003

git-svn-id: svn://svn.chromium.org/blink/trunk@169664 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/web/WebRuntimeFeatures.cpp

@@ -38,12 +38,6 @@ using namespace WebCore;
 
 namespace blink {
 
-void WebRuntimeFeatures::enableStableFeatures(bool enable)
-{
-    // FIXME: This entire method should be removed once it is no longer called by Chromium.
-    ASSERT(enable);
-}
-
 void WebRuntimeFeatures::enableExperimentalFeatures(bool enable)
 {
     RuntimeEnabledFeatures::setExperimentalFeaturesEnabled(enable);

third_party/WebKit/public/web/WebRuntimeFeatures.h

@@ -36,12 +36,9 @@
 namespace blink {
 
 // This class is used to enable runtime features of Blink.
-// All features are disabled by default.
-// Most clients should call enableStableFeatures() to enable
-// features Blink has made API commitments to.
+// Stable features are enabled by default.
 class WebRuntimeFeatures {
 public:
-    BLINK_EXPORT static void enableStableFeatures(bool);
     BLINK_EXPORT static void enableExperimentalFeatures(bool);
     BLINK_EXPORT static void enableTestOnlyFeatures(bool);