Call DumpRenderTree directly from test.dart instead of using the drt-trampoline.py indirection

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index 64aa4020b569c451f2405e642008485febe9b5e7..b72fb7115b8b38c95fde0dc244dfcba5d97079b5 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -789,6 +789,7 @@ class StandardTestSuite extends TestSuite {
                           String testName,
                           Object expectations,
                           bool isWrappingRequired) {
+    // TODO(kustermann/ricow): This method should be refactored.
     Map optionsFromFile = info.optionsFromFile;
     Path filePath = info.filePath;
     String filename = filePath.toString();
@@ -914,6 +915,14 @@ class StandardTestSuite extends TestSuite {
       int subtestIndex = 0;
       // Construct the command that executes the browser test
       do {
+        List<Command> commandSet = new List<Command>.from(commands);
+        if (subtestIndex != 0) {
+          // NOTE: The first time we enter this loop, all the compilation 
+          // commands will be executed. On subsequent loop iterations, we 
+          // don't need to do any compilations. Thus we set "commandSet = []".
+          commandSet = [];
+        }
+
         List<String> args = <String>[];
         String fullHtmlPath = htmlPath.startsWith('http:') ? htmlPath :
             (htmlPath.startsWith('/') ?
@@ -923,6 +932,7 @@ class StandardTestSuite extends TestSuite {
             && subtestNames.length > 0) {
           fullHtmlPath = '${fullHtmlPath}#${subtestNames[subtestIndex]}';
         }
+
         if (TestUtils.usesWebDriver(runtime)) {
           args = [
               dartDir.append('tools/testing/run_selenium.py').toNativePath(),
@@ -932,40 +942,52 @@ class StandardTestSuite extends TestSuite {
           if (runtime == 'dartium') {
             args.add('--executable=$dartiumFilename');
           }
-        } else {
-          args = [
-              dartDir.append('tools/testing/drt-trampoline.py').toNativePath(),
-              dumpRenderTreeFilename,
-              '--no-timeout'
-          ];
-          if (compiler == 'none') {
-            String packageRoot =
-                packageRootArgument(optionsFromFile['packageRoot']);
-            if (packageRoot != null) {
-              args.add(packageRoot);
-            }
+          if (subtestIndex != 0) {
+            args.add('--force-refresh');
           }
-          if (runtime == 'drt' &&
-              (compiler == 'none' || compiler == 'dart2dart')) {
-            var dartFlags = ['--ignore-unrecognized-flags'];
+          commandSet.add(new Command('python', args));
+        } else {
+          Expect.isTrue(runtime == "drt");
+
+          var dartFlags = [];
+          var dumpRenderTreeOptions = [];
+          var packageRootUri;
+
+          dumpRenderTreeOptions.add('--no-timeout');
+
+          if (compiler == 'none' || compiler == 'dart2dart') {
+            dartFlags.add('--ignore-unrecognized-flags');
             if (configuration["checked"]) {
               dartFlags.add('--enable_asserts');
               dartFlags.add("--enable_type_checks");
             }
             dartFlags.addAll(vmOptions);
-            args.add('--dart-flags=${Strings.join(dartFlags, " ")}');
           }
-          args.add(fullHtmlPath);
+          if (compiler == 'none') {
+            var packageRoot = packageRootArgument(
+                optionsFromFile['packageRoot']);
+            if (packageRoot != null) {
+              var absolutePath = TestUtils.absolutePath(new Path(packageRoot));
+              packageRootUri = new Uri.fromComponents(
+                  scheme: 'file',
+                  path: absolutePath.toString());
+            }
+          }
+
           if (expectedOutput != null) {
-            args.add('--out-expectation=${expectedOutput.toNativePath()}');
+            if (expectedOutput.toNativePath().endsWith('.png')) {
+              // pixel tests are specified by running DRT "foo.html'-p"
+              dumpRenderTreeOptions.add('--notree');
+              fullHtmlPath = "${fullHtmlPath}'-p";
+            }
           }
+          commandSet.add(new DumpRenderTreeCommand(dumpRenderTreeFilename,
+                                                   fullHtmlPath,
+                                                   dumpRenderTreeOptions,
+                                                   dartFlags,
+                                                   packageRootUri,
+                                                   expectedOutput));
         }
-        List<Command> commandSet = new List<Command>.from(commands);
-        if (subtestIndex != 0) {
-         commandSet = [];
-         if(TestUtils.usesWebDriver(runtime)) args.add('--force-refresh');
-        }
-        commandSet.add(new Command('python', args));
 
         // Create BrowserTestCase and queue it.
         String testDisplayName = '$suiteName/$testName';