Add support for profile-based startup optimizations.

pkg/compiler/lib/src/options.dart

Index: pkg/compiler/lib/src/options.dart
diff --git a/pkg/compiler/lib/src/options.dart b/pkg/compiler/lib/src/options.dart
index dfb603ab9a01e0692eccca2189c65c5e175d9426..1b57713a7f581a7cebf6a06404de1d90e84fb7e6 100644
--- a/pkg/compiler/lib/src/options.dart
+++ b/pkg/compiler/lib/src/options.dart
@@ -230,6 +230,11 @@ class CompilerOptions implements DiagnosticOptions {
   /// during each phase and a time-breakdown between phases at the end.
   final bool verbose;
 
+  /// Track allocations in the JS output.
+  ///
+  /// This is an experimental feature.
+  final bool trackAllocations;
+
   // -------------------------------------------------
   // Options for deprecated features
   // -------------------------------------------------
@@ -299,6 +304,7 @@ class CompilerOptions implements DiagnosticOptions {
         sourceMapUri: _extractUriOption(options, '--source-map='),
         strips: _extractCsvOption(options, '--force-strip='),
         testMode: _hasOption(options, Flags.testMode),
+        trackAllocations: _hasOption(options, Flags.trackAllocations),
         trustJSInteropTypeAnnotations:
             _hasOption(options, Flags.trustJSInteropTypeAnnotations),
         trustPrimitives: _hasOption(options, Flags.trustPrimitives),
@@ -362,6 +368,7 @@ class CompilerOptions implements DiagnosticOptions {
       Uri sourceMapUri: null,
       List<String> strips: const [],
       bool testMode: false,
+      bool trackAllocations: false,
       bool trustJSInteropTypeAnnotations: false,
       bool trustPrimitives: false,
       bool trustTypeAnnotations: false,
@@ -435,6 +442,7 @@ class CompilerOptions implements DiagnosticOptions {
         sourceMapUri: sourceMapUri,
         strips: strips,
         testMode: testMode,
+        trackAllocations: trackAllocations,
         trustJSInteropTypeAnnotations: trustJSInteropTypeAnnotations,
         trustPrimitives: trustPrimitives,
         trustTypeAnnotations: trustTypeAnnotations,
@@ -486,6 +494,7 @@ class CompilerOptions implements DiagnosticOptions {
       this.sourceMapUri: null,
       this.strips: const [],
       this.testMode: false,
+      this.trackAllocations: false,
       this.trustJSInteropTypeAnnotations: false,
       this.trustPrimitives: false,
       this.trustTypeAnnotations: false,
@@ -544,6 +553,7 @@ class CompilerOptions implements DiagnosticOptions {
       sourceMapUri,
       strips,
       testMode,
+      trackAllocations,
       trustJSInteropTypeAnnotations,
       trustPrimitives,
       trustTypeAnnotations,
@@ -609,6 +619,7 @@ class CompilerOptions implements DiagnosticOptions {
         sourceMapUri: sourceMapUri ?? options.sourceMapUri,
         strips: strips ?? options.strips,
         testMode: testMode ?? options.testMode,
+        trackAllocations: trackAllocations ?? options.trackAllocations,
         trustJSInteropTypeAnnotations: trustJSInteropTypeAnnotations ??
             options.trustJSInteropTypeAnnotations,
         trustPrimitives: trustPrimitives ?? options.trustPrimitives,