[Worklets] Add basic debugging to main thread worklets.

third_party/WebKit/Source/core/inspector/InspectorInstrumentation.cpp

 /*
 * Copyright (C) 2011 Google 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.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 #include "core/fetch/FetchInitiatorInfo.h"
 #include "core/frame/FrameHost.h"
 #include "core/inspector/InspectorCSSAgent.h"
 #include "core/inspector/InspectorConsoleAgent.h"
 #include "core/inspector/InspectorDebuggerAgent.h"
 #include "core/inspector/InspectorProfilerAgent.h"
 #include "core/inspector/InspectorResourceAgent.h"
 #include "core/inspector/InstrumentingAgents.h"
 #include "core/inspector/WorkerInspectorController.h"
 #include "core/page/Page.h"
+#include "core/workers/MainThreadWorkletGlobalScope.h"
 #include "core/workers/WorkerGlobalScope.h"
 
 namespace blink {
 
 namespace {
 
 WillBePersistentHeapHashSet<RawPtrWillBeWeakMember<InstrumentingAgents>>& instrumentingAgentsSet()
 {
     DEFINE_STATIC_LOCAL(WillBePersistentHeapHashSet<RawPtrWillBeWeakMember<InstrumentingAgents>>, instrumentingAgentsSet, ());
     return instrumentingAgentsSet;
@@ skipping 111 matching lines @@
 {
     if (!workerGlobalScope)
         return 0;
     return instrumentationForWorkerGlobalScope(workerGlobalScope);
 }
 
 InstrumentingAgents* instrumentingAgentsForNonDocumentContext(ExecutionContext* context)
 {
     if (context->isWorkerGlobalScope())
         return instrumentationForWorkerGlobalScope(toWorkerGlobalScope(context));
+
+    if (context->isWorkletGlobalScope()) {

[pfeldman, 2016/03/15 00:34:56]

Is this only used for the scriptImported instrumentation? It is unfortunate that
we get into the ForNonDocument code path for something that runs on the main
thread. Could you change the call site to use owner local frame in the
instrumentation?

[ikilpatrick, 2016/03/17 16:46:44]

This is used for the willExecuteScript instrumentation, I.e.

#1  0x000000000262d601 in
blink::InspectorInstrumentation::instrumentingAgentsFor 
#2  0x0000000003dfa0ae in blink::InspectorInstrumentation::willExecuteScript 
#3  0x0000000003df6896 in blink::V8ScriptRunner::runCompiledScript 
#4  0x0000000003e0fc3a in blink::WorkerOrWorkletScriptController::evaluate 

I don't think it would make sense to change V8ScriptRunner::runCompiledScript.

Thoughts?

+        LocalFrame* frame = toMainThreadWorkletGlobalScope(context)->frame();
+        if (frame)
+            return instrumentingAgentsFor(frame);
+    }
+
     return 0;
 }
 
 } // namespace InspectorInstrumentation
 
 namespace InstrumentationEvents {
 const char PaintSetup[] = "PaintSetup";
 const char Paint[] = "Paint";
 const char Layer[] = "Layer";
 const char RequestMainThreadFrame[] = "RequestMainThreadFrame";
@@ skipping 12 matching lines @@
 };
 
 InstrumentingAgents* instrumentationForWorkerGlobalScope(WorkerGlobalScope* workerGlobalScope)
 {
     if (WorkerInspectorController* controller = workerGlobalScope->workerInspectorController())
         return controller->m_instrumentingAgents.get();
     return 0;
 }
 
 } // namespace blink