Introduced DevTools API Performance::SetTimeDomain().

DevTools performance metrics now allows collection and reporting of
duration related metrics using monotonically increasing abstract time
and thread running time.

Change-Id: Ica54cc291ba456c8dcc6a47a962e99a87cb8a475
Reviewed-on: https://chromium-review.googlesource.com/1247528Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Peter Kvitek <kvitekp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595262}

third_party/blink/renderer/core/inspector/browser_protocol.pdl

@@ -5485,6 +5485,18 @@ domain Performance
   # Enable collecting and reporting metrics.
   command enable
 
+  # Sets time domain to use for collecting and reporting duration metrics.
+  # Note that this must be called before enabling metrics collection. Calling
+  # this method while metrics collection is enabled returns an error.
+  experimental command setTimeDomain
+    parameters
+      # Time domain
+      enum timeDomain
+        # Use monotonically increasing abstract time (default).
+        timeTicks
+        # Use thread running time.
+        threadTicks
+
   # Retrieve current values of run-time metrics.
   command getMetrics
     returns

third_party/blink/renderer/core/inspector/inspector_performance_agent.cc

@@ -83,11 +83,39 @@ void AppendMetric(protocol::Array<protocol::Performance::Metric>* container,
                          .setValue(value)
                          .build());
 }
+}  // namespace
+
+Response InspectorPerformanceAgent::setTimeDomain(const String& time_domain) {
+  if (enabled_.Get()) {
+    return Response::Error(
+        "Cannot set time domain while performance metrics collection"
+        " is enabled.");
+  }
+
+  using namespace protocol::Performance::SetTimeDomain;
+
+  if (time_domain == TimeDomainEnum::TimeTicks) {
+    use_thread_ticks_ = false;
+  } else if (time_domain == TimeDomainEnum::ThreadTicks) {
+    if (!base::ThreadTicks::IsSupported()) {
+      return Response::Error("Thread time is not supported on this platform.");
+    }
+    base::ThreadTicks::WaitUntilInitialized();
+    use_thread_ticks_ = true;
+  } else {
+    return Response::Error("Invalid time domain specification.");
+  }
 
-TimeTicks GetTimeTicksNow() {
-  return base::subtle::TimeTicksNowIgnoringOverride();
+  return Response::OK();
+}
+
+TimeTicks InspectorPerformanceAgent::GetTimeTicksNow() {
+  return use_thread_ticks_
+             ? base::TimeTicks() +
+                   base::TimeDelta::FromMicroseconds(
+                       base::ThreadTicks::Now().since_origin().InMicroseconds())
+             : base::subtle::TimeTicksNowIgnoringOverride();
 }
-}  // namespace
 
 Response InspectorPerformanceAgent::getMetrics(
     std::unique_ptr<protocol::Array<protocol::Performance::Metric>>*

third_party/blink/renderer/core/inspector/inspector_performance_agent.h

@@ -42,6 +42,7 @@ class CORE_EXPORT InspectorPerformanceAgent final
   // Performance protocol domain implementation.
   protocol::Response enable() override;
   protocol::Response disable() override;
+  protocol::Response setTimeDomain(const String& time_domain) override;
   protocol::Response getMetrics(
       std::unique_ptr<protocol::Array<protocol::Performance::Metric>>*
           out_result) override;
@@ -69,6 +70,7 @@ class CORE_EXPORT InspectorPerformanceAgent final
   void ScriptStarts();
   void ScriptEnds();
   void InnerEnable();
+  TimeTicks GetTimeTicksNow();
 
   Member<InspectedFrames> inspected_frames_;
   TimeDelta layout_duration_;
@@ -85,6 +87,7 @@ class CORE_EXPORT InspectorPerformanceAgent final
   unsigned long long recalc_style_count_ = 0;
   int script_call_depth_ = 0;
   int layout_depth_ = 0;
+  bool use_thread_ticks_ = false;
   InspectorAgentState::Boolean enabled_;
   DISALLOW_COPY_AND_ASSIGN(InspectorPerformanceAgent);
 };

third_party/blink/tools/audit_non_blink_usage.py

@@ -52,6 +52,7 @@ _CONFIG = [
             'base::Time',
             'base::TimeDelta',
             'base::TimeTicks',
+            'base::ThreadTicks',
             'base::UnguessableToken',
             'base::UnsafeSharedMemoryRegion',
             'base::WeakPtr',