Deprecate and disable CollectorLegacy, simplify startup

user/src/com/google/gwt/core/client/impl/Impl.java

@@ -28,12 +28,6 @@
  */
 public final class Impl {
 
-  static {
-    if (GWT.isScript() && StackTraceCreator.collector != null) {
-      // Just enforces loading of StackTraceCreator early on, nothing else to do here...
-    }
-  }
-
   private static final int WATCHDOG_ENTRY_DEPTH_CHECK_INTERVAL_MS = 2000;
 
   /**

user/src/com/google/gwt/core/client/impl/StackTraceCreator.java

@@ -65,6 +65,7 @@ abstract static class Collector {
    * This legacy {@link Collector} simply crawls <code>arguments.callee.caller</code> for browsers
    * that doesn't support {@code Error.stack} property.
    */
+  @Deprecated
   static class CollectorLegacy extends Collector {
 
     @Override
@@ -306,11 +307,11 @@ public StackTraceElement[] getStackTrace(Object ignored) {
    * Collect necessary information to construct stack trace trace later in time.
    */
   public static void captureStackTrace(Object error) {
-    collector.collect(error);
+    getCollector().collect(error);
   }
 
   public static StackTraceElement[] constructJavaStackTrace(Throwable thrown) {
-    StackTraceElement[] stackTrace = collector.getStackTrace(thrown);
+    StackTraceElement[] stackTrace = getCollector().getStackTrace(thrown);
     return dropInternalFrames(stackTrace);
   }
 
@@ -338,26 +339,10 @@ private static <T> void splice(Object[] arr, int length) {
     }
   }
 
-  // Visible for testing
-  static final Collector collector;
-
-  static {
-    // Ensure old Safari falls back to legacy Collector implementation.
-    boolean enforceLegacy = !supportsErrorStack();
-    Collector c = GWT.create(Collector.class);
-    collector = (c instanceof CollectorModern && enforceLegacy) ? new CollectorLegacy() : c;
+  static Collector getCollector() {
+    return GWT.create(Collector.class);
   }
 
-  private static native boolean supportsErrorStack() /*-{
-    // Error.stackTraceLimit is cheaper to check and available in both IE and Chrome
-    if (Error.stackTraceLimit > 0) {
-      $wnd.Error.stackTraceLimit = Error.stackTraceLimit = 64;
-      return true;
-    }
-
-    return "stack" in new Error();
-  }-*/;
-
   private static native JsArrayString getFnStack(Object e) /*-{
     return (e && e["fnStack"]) ? e["fnStack"] : [];
   }-*/;

user/test/com/google/gwt/core/client/impl/StackTraceEmulTest.java

@@ -37,7 +37,7 @@ protected String[] getTraceJse(Object thrown) {
 
   @Override
   public void testCollectorType() {
-    assertTrue(StackTraceCreator.collector instanceof StackTraceCreator.CollectorEmulated);
+    assertTrue(StackTraceCreator.getCollector() instanceof StackTraceCreator.CollectorEmulated);
   }
 
   /**

user/test/com/google/gwt/core/client/impl/StackTraceNativeTest.java

@@ -17,7 +17,6 @@
 
 import static com.google.gwt.core.client.impl.StackTraceExamples.TYPE_ERROR;
 
-import com.google.gwt.core.client.impl.StackTraceCreator.CollectorLegacy;
 import com.google.gwt.core.client.impl.StackTraceCreator.CollectorModern;
 import com.google.gwt.junit.DoNotRunWith;
 import com.google.gwt.junit.Platform;
@@ -49,7 +48,7 @@ protected String[] getTraceJava() {
   @Override
   protected String[] getTraceRecursion() {
     // First two frames are optional as they are automatically stripped by EDGE.
-    final String[] expectedModern = {
+    return new String[]{
         "?" + Impl.getNameOf("@java.lang.Throwable::new(Ljava/lang/String;)"),
         "?" + Impl.getNameOf("@java.lang.Exception::new(Ljava/lang/String;)"),
         Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::throwException2(*)"),
@@ -62,16 +61,6 @@ protected String[] getTraceRecursion() {
         Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::getLiveException(*)"),
         Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceTestBase::testTraceRecursion()"),
     };
-
-    final String[] expectedLegacy = {
-        Impl.getNameOf("@java.lang.Throwable::new(Ljava/lang/String;)"),
-        Impl.getNameOf("@java.lang.Exception::new(Ljava/lang/String;)"),
-        Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::throwException2(*)"),
-        Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::throwException1(*)"),
-        Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::throwRecursive(*)"),
-    };
-
-    return isLegacyCollector() ? expectedLegacy : expectedModern;
   }
 
   @Override
@@ -87,12 +76,6 @@ protected String[] getTraceJse(Object thrown) {
         Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceTestBase::assertJse(*)"),
     };
 
-    final String[] limited_wrap = {
-        Impl.getNameOf("@com.google.gwt.lang.Exceptions::toJava(*)"),
-        Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::getLiveException(*)"),
-        Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceTestBase::assertJse(*)"),
-    };
-
     final String[] limited_fillInStackTrace = {
         Impl.getNameOf("@java.lang.Throwable::fillInStackTrace()"),
         Impl.getNameOf("@com.google.gwt.core.client.impl.StackTraceExamples::getLiveException(*)"),
@@ -101,28 +84,14 @@ protected String[] getTraceJse(Object thrown) {
 
     // For legacy browsers and non-error javascript exceptions (e.g. throw "string"), we can only
     // construct stack trace from the catch block and below.
-    return isLegacyCollector()
-        ? limited_wrap : (thrown != TYPE_ERROR ? limited_fillInStackTrace : full);
+    return thrown != TYPE_ERROR ? limited_fillInStackTrace : full;
   }
 
   public void testCollectorType() {
-    if (isSafari5()) {
-      assertTrue(isLegacyCollector());
-    } else {
-      assertTrue(isModernCollector());
-    }
-  }
-
-  private static boolean isLegacyCollector() {
-    return StackTraceCreator.collector instanceof CollectorLegacy;
+    assertTrue(isModernCollector());
   }
 
   private static boolean isModernCollector() {
-    return StackTraceCreator.collector instanceof CollectorModern;
+    return StackTraceCreator.getCollector() instanceof CollectorModern;
   }
-
-  private static native boolean isSafari5() /*-{
-    return navigator.userAgent.match(' Safari/') && !navigator.userAgent.match(' Chrom')
-        && !!navigator.userAgent.match(' Version/5.');
-  }-*/;
 }