Convert performance monitor to the subscription model.

third_party/WebKit/Source/core/timing/Performance.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 17 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/timing/Performance.h"
 
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8ObjectBuilder.h"
 #include "core/dom/Document.h"
 #include "core/frame/LocalFrame.h"
-#include "core/frame/PerformanceMonitor.h"
+#include "core/frame/UseCounter.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/origin_trials/OriginTrials.h"
 #include "core/timing/PerformanceTiming.h"
 
+static const double kLongTaskThreshold = 0.05;
+
+static const char kUnknownAttribution[] = "unknown";
+static const char kAmbugiousAttribution[] = "multiple-contexts";
+static const char kSameOriginAttribution[] = "same-origin";
+static const char kAncestorAttribution[] = "cross-origin-ancestor";
+static const char kDescendantAttribution[] = "cross-origin-descendant";
+static const char kCrossOriginAttribution[] = "cross-origin-unreachable";
+
 namespace blink {
 
 static double toTimeOrigin(LocalFrame* frame) {
   if (!frame)
     return 0.0;
 
   Document* document = frame->document();
   if (!document)
     return 0.0;
 
   DocumentLoader* loader = document->loader();
   if (!loader)
     return 0.0;
 
   return loader->timing().referenceMonotonicTime();
 }
 
 Performance::Performance(LocalFrame* frame)
     : PerformanceBase(toTimeOrigin(frame)), DOMWindowProperty(frame) {}
 
-Performance::~Performance() {
-  if (frame())
-    PerformanceMonitor::performanceObserverRemoved(this);
-}
-
-void Performance::frameDestroyed() {

[caseq, 2016/11/09 00:41:11]

Shouldn't you unsubscribe when frame is gone?

[pfeldman, 2016/11/09 01:39:14]

Done.

[pfeldman, 2016/11/09 01:39:14]

Done.

-  PerformanceMonitor::performanceObserverRemoved(this);
-  DOMWindowProperty::frameDestroyed();
-}
+Performance::~Performance() {}
 
 ExecutionContext* Performance::getExecutionContext() const {
   if (!frame())
     return nullptr;
   return frame()->document();
 }
 
 MemoryInfo* Performance::memory() {
   return MemoryInfo::create();
 }
@@ skipping 10 matching lines @@
     m_timing = PerformanceTiming::create(frame());
 
   return m_timing.get();
 }
 
 void Performance::updateLongTaskInstrumentation() {
   DCHECK(frame());
   if (!frame()->document() ||
       !OriginTrials::longTaskObserverEnabled(frame()->document()))
     return;
-  LocalFrame* localRoot = frame()->localFrameRoot();
-  DCHECK(localRoot);
 
-  if (hasObserverFor(PerformanceEntry::LongTask))
-    PerformanceMonitor::performanceObserverAdded(this);
-  else
-    PerformanceMonitor::performanceObserverRemoved(this);
+  if (hasObserverFor(PerformanceEntry::LongTask)) {
+    UseCounter::count(frame()->localFrameRoot(), UseCounter::LongTaskObserver);
+    frame()->performanceMonitor()->subscribe(PerformanceMonitor::kLongTask,
+                                             kLongTaskThreshold, this);
+  } else {
+    frame()->performanceMonitor()->unsubscribeAll(this);
+  }
 }
 
 ScriptValue Performance::toJSONForBinding(ScriptState* scriptState) const {
   V8ObjectBuilder result(scriptState);
   result.add("timing", timing()->toJSONForBinding(scriptState));
   result.add("navigation", navigation()->toJSONForBinding(scriptState));
   return result.scriptValue();
 }
 
 DEFINE_TRACE(Performance) {
   visitor->trace(m_navigation);
   visitor->trace(m_timing);
   DOMWindowProperty::trace(visitor);
   PerformanceBase::trace(visitor);
+  PerformanceMonitor::Client::trace(visitor);
+}
+
+static bool canAccessOrigin(Frame* frame1, Frame* frame2) {
+  SecurityOrigin* securityOrigin1 =
+      frame1->securityContext()->getSecurityOrigin();
+  SecurityOrigin* securityOrigin2 =
+      frame2->securityContext()->getSecurityOrigin();
+  return securityOrigin1->canAccess(securityOrigin2);
+}
+
+/**
+ * Report sanitized name based on cross-origin policy.
+ * See detailed Security doc here: http://bit.ly/2duD3F7
+ */
+// static
+std::pair<String, DOMWindow*> Performance::sanitizedAttribution(
+    const HeapHashSet<Member<Frame>>& frames,
+    Frame* observerFrame) {
+  if (frames.size() == 0) {
+    // Unable to attribute as no script was involved.
+    return std::make_pair(kUnknownAttribution, nullptr);
+  }
+  if (frames.size() > 1) {
+    // Unable to attribute, multiple script execution contents were involved.
+    return std::make_pair(kAmbugiousAttribution, nullptr);
+  }
+  // Exactly one culprit location, attribute based on origin boundary.
+  DCHECK_EQ(1u, frames.size());
+  Frame* culpritFrame = *frames.begin();
+  DCHECK(culpritFrame);
+  if (canAccessOrigin(observerFrame, culpritFrame)) {
+    // From accessible frames or same origin, return culprit location URL.
+    return std::make_pair(kSameOriginAttribution, culpritFrame->domWindow());
+  }
+  // For cross-origin, if the culprit is the descendant or ancestor of
+  // observer then indicate the *closest* cross-origin frame between
+  // the observer and the culprit, in the corresponding direction.
+  if (culpritFrame->tree().isDescendantOf(observerFrame)) {
+    // If the culprit is a descendant of the observer, then walk up the tree
+    // from culprit to observer, and report the *last* cross-origin (from
+    // observer) frame.  If no intermediate cross-origin frame is found, then
+    // report the culprit directly.
+    Frame* lastCrossOriginFrame = culpritFrame;
+    for (Frame* frame = culpritFrame; frame != observerFrame;
+         frame = frame->tree().parent()) {
+      if (!canAccessOrigin(observerFrame, frame)) {
+        lastCrossOriginFrame = frame;
+      }
+    }
+    return std::make_pair(kDescendantAttribution,
+                          lastCrossOriginFrame->domWindow());
+  }
+  if (observerFrame->tree().isDescendantOf(culpritFrame)) {
+    return std::make_pair(kAncestorAttribution, nullptr);
+  }
+  return std::make_pair(kCrossOriginAttribution, nullptr);
+}
+
+void Performance::reportLongTask(
+    double startTime,
+    double endTime,
+    const HeapHashSet<Member<Frame>>& contextFrames) {
+  std::pair<String, DOMWindow*> attribution =
+      Performance::sanitizedAttribution(contextFrames, frame());

[caseq, 2016/11/09 00:41:12]

frame() can be null here, right?

[pfeldman, 2016/11/09 01:39:14]

Not anymore.

+  addLongTaskTiming(startTime, endTime, attribution.first, attribution.second);
 }
 
 }  // namespace blink