[vm-service] Encode ticks directly as integers, since they are expect to stay in JS integer range.

runtime/observatory/lib/src/cpu_profile/cpu_profile.dart

Index: runtime/observatory/lib/src/cpu_profile/cpu_profile.dart
diff --git a/runtime/observatory/lib/src/cpu_profile/cpu_profile.dart b/runtime/observatory/lib/src/cpu_profile/cpu_profile.dart
index 1ce26489a63823acd61262e8d430f0735330f113..87c4213219abeefdbf20c4beaea149013ea1ab09 100644
--- a/runtime/observatory/lib/src/cpu_profile/cpu_profile.dart
+++ b/runtime/observatory/lib/src/cpu_profile/cpu_profile.dart
@@ -477,9 +477,11 @@ class ProfileCode implements M.ProfileCode {
     assert(profileTicks != null);
     assert((profileTicks.length % 3) == 0);
     for (var i = 0; i < profileTicks.length; i += 3) {
+      // TODO(observatory): Address is not necessarily representable as a JS
+      // integer.
       var address = int.parse(profileTicks[i], radix: 16);
-      var exclusive = int.parse(profileTicks[i + 1]);
-      var inclusive = int.parse(profileTicks[i + 2]);
+      var exclusive = profileTicks[i + 1];
+      var inclusive = profileTicks[i + 2];
       var tick = new CodeTick(exclusive, inclusive);
       addressTicks[address] = tick;
 
@@ -524,8 +526,8 @@ class ProfileCode implements M.ProfileCode {
     } else if (code.kind == M.CodeKind.native) {
       attributes.add('native');
     }
-    inclusiveTicks = int.parse(data['inclusiveTicks']);
-    exclusiveTicks = int.parse(data['exclusiveTicks']);
+    inclusiveTicks = data['inclusiveTicks'];
+    exclusiveTicks = data['exclusiveTicks'];
 
     normalizedExclusiveTicks = exclusiveTicks / profile.sampleCount;
 
@@ -690,8 +692,8 @@ class ProfileFunction implements M.ProfileFunction {
     profileCodes.sort(_sortCodes);
 
     _addKindBasedAttributes(attributes);
-    exclusiveTicks = int.parse(data['exclusiveTicks']);
-    inclusiveTicks = int.parse(data['inclusiveTicks']);
+    exclusiveTicks = data['exclusiveTicks'];
+    inclusiveTicks = data['inclusiveTicks'];
 
     normalizedExclusiveTicks = exclusiveTicks / profile.sampleCount;
     normalizedInclusiveTicks = inclusiveTicks / profile.sampleCount;