[coverage] Change time format in recently added protocol messages

The time was reported in milliseconds, but should be reported in seconds
instead.

TBR=ulan@chromium.org, szuend@chromium.org

Change-Id: I171cdb0107cd522b0d62ac6ed4edfacf7599da0b
Bug: chromium:1022031
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1997137Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65727}

include/js_protocol.pdl

@@ -825,7 +825,7 @@ domain Profiler
       # Collect block-based coverage.
       optional boolean detailed
     returns
-      # The timestamp (in milliseconds) the coverage update was taken in the backend.
+      # Monotonically increasing time (in seconds) when the coverage update was taken in the backend.
       number timestamp
 
   # Enable type profile.
@@ -849,7 +849,7 @@ domain Profiler
     returns
       # Coverage data for the current isolate.
       array of ScriptCoverage result
-      # The timestamp (in milliseconds) the coverage update was taken in the backend.
+      # Monotonically increasing time (in seconds) when the coverage update was taken in the backend.
       number timestamp
 
   # Collect type profile.

src/inspector/v8-profiler-agent-impl.cc

@@ -300,7 +300,7 @@ Response V8ProfilerAgentImpl::startPreciseCoverage(Maybe<bool> callCount,
   if (!m_enabled) return Response::Error("Profiler is not enabled");
   *out_timestamp =
       (v8::base::TimeTicks::HighResolutionNow() - v8::base::TimeTicks())
-          .InMilliseconds();
+          .InSecondsF();
   bool callCountValue = callCount.fromMaybe(false);
   bool detailedValue = detailed.fromMaybe(false);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageStarted, true);
@@ -412,7 +412,7 @@ Response V8ProfilerAgentImpl::takePreciseCoverage(
   v8::debug::Coverage coverage = v8::debug::Coverage::CollectPrecise(m_isolate);
   *out_timestamp =
       (v8::base::TimeTicks::HighResolutionNow() - v8::base::TimeTicks())
-          .InMilliseconds();
+          .InSecondsF();
   return coverageToProtocol(m_session->inspector(), coverage, out_result);
 }