[debug] do not report unnecessary coverage data.

test/inspector/cpu-profiler/coverage.js

Index: test/inspector/cpu-profiler/coverage.js
diff --git a/test/inspector/cpu-profiler/coverage.js b/test/inspector/cpu-profiler/coverage.js
index b50180e69af125f4572efc663f8e196b4c925dec..c1b8a95c1b57ccaae165cfc2f18297bf431f99f1 100644
--- a/test/inspector/cpu-profiler/coverage.js
+++ b/test/inspector/cpu-profiler/coverage.js
@@ -34,6 +34,22 @@ function h() {
 f(3);
 `;
 
+var nested =
+`
+var f = (function outer() {
+  function nested_0() {
+    return function nested_1() {
+      return function nested_2() {
+        return function nested_3() {}
+      }
+    }
+  }
+  function nested_4() {}
+  return nested_0();
+})();
+f()()();
+`;
+
 InspectorTest.log("Test collecting code coverage data with Profiler.collectCoverage.");
 
 function ClearAndGC() {
@@ -78,8 +94,8 @@ InspectorTest.runTestSuite([
       .then(Protocol.Profiler.startPreciseCoverage)
       .then(() => Protocol.Runtime.compileScript({ expression: source, sourceURL: "1", persistScript: true }))
       .then((result) => Protocol.Runtime.runScript({ scriptId: result.result.scriptId }))
-      .then(ClearAndGC)
       .then(InspectorTest.logMessage)
+      .then(ClearAndGC)
       .then(Protocol.Profiler.takePreciseCoverage)
       .then(LogSorted)
       .then(Protocol.Profiler.takePreciseCoverage)
@@ -188,4 +204,44 @@ InspectorTest.runTestSuite([
       .then(ClearAndGC)
       .then(next);
   },
+  function testPreciseEmptyScriptCoverageEntries(next)
+  {
+    // Enabling the debugger holds onto script objects even though its
+    // functions can be garbage collected. We would get empty ScriptCoverage
+    // entires unless we remove them.
+    Protocol.Debugger.enable()
+      .then(Protocol.Runtime.enable)
+      .then(() => Protocol.Runtime.compileScript({ expression: source, sourceURL: "7", persistScript: true }))
+      .then((result) => Protocol.Runtime.runScript({ scriptId: result.result.scriptId }))
+      .then(ClearAndGC)
+      .then(Protocol.Profiler.enable)
+      .then(() => Protocol.Profiler.startPreciseCoverage({binary: true}))
+      .then(Protocol.Profiler.takePreciseCoverage)
+      .then(LogSorted)
+      .then(Protocol.Profiler.stopPreciseCoverage)
+      .then(Protocol.Profiler.disable)
+      .then(Protocol.Runtime.disable)
+      .then(Protocol.Debugger.disable)
+      .then(ClearAndGC)
+      .then(next);
+  },
+  function testPreciseCoveragePartial(next)
+  {
+    Protocol.Runtime.enable()
+      .then(Protocol.Profiler.enable)
+      .then(Protocol.Profiler.startPreciseCoverage)
+      .then(() => Protocol.Runtime.compileScript({ expression: nested, sourceURL: "1", persistScript: true }))
+      .then((result) => Protocol.Runtime.runScript({ scriptId: result.result.scriptId }))
+      .then(InspectorTest.logMessage)
+      .then(Protocol.Profiler.takePreciseCoverage)
+      .then(LogSorted)
+      .then(() => Protocol.Runtime.evaluate({ expression: "f()" }))
+      .then(Protocol.Profiler.takePreciseCoverage)
+      .then(LogSorted)
+      .then(Protocol.Profiler.stopPreciseCoverage)
+      .then(Protocol.Profiler.disable)
+      .then(Protocol.Runtime.disable)
+      .then(ClearAndGC)
+      .then(next);
+  },
 ]);