Adds a crash key to V8EventListener to help diagnose crbug.com/621730 .

This change can be reverted after a day or two of data.

BUG=621730
R=haraken@chromium.org, rsesek@chromium.org

Review URL: https://codereview.chromium.org/2107773002 .

Cr-Commit-Position: refs/heads/master@{#402609}

blimp/engine/app/blimp_engine_crash_keys.cc

@@ -73,6 +73,9 @@ size_t RegisterEngineCrashKeys() {
       // Temporary for https://crbug.com/612711.
       { "aci_wrong_sp_extension_id", crash_keys::kSmallSize },
 
+      // Temporary for http://crbug.com/621730.
+      { "postmessage_script_info", crash_keys::kLargeSize },
+
       // Temporary for https://crbug.com/616149.
       { "existing_extension_pref_value_type", crash_keys::kSmallSize },
     };

chrome/common/crash_keys.cc

@@ -194,6 +194,9 @@ size_t RegisterChromeCrashKeys() {
     // Temporary for https://crbug.com/612711.
     { "aci_wrong_sp_extension_id", kSmallSize },
 
+    // Temporary for http://crbug.com/621730
+    { "postmessage_script_info", kLargeSize },
+
     // Temporary for https://crbug.com/616149.
     { "existing_extension_pref_value_type", crash_keys::kSmallSize },
   };

third_party/WebKit/Source/bindings/core/v8/V8EventListener.cpp

@@ -33,7 +33,9 @@
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "core/dom/Document.h"
+#include "core/events/Event.h"
 #include "core/frame/LocalFrame.h"
+#include "wtf/debug/CrashLogging.h"
 
 namespace blink {
 
@@ -90,6 +92,28 @@ v8::Local<v8::Value> V8EventListener::callListenerFunction(ScriptState* scriptSt
     if (scriptState->world().isMainWorld() && !frame->script().canExecuteScripts(AboutToExecuteScript))
         return v8::Local<v8::Value>();
 
+    // Temporary instrumentation for http://crbug.com/621730.
+    String scriptInfo;
+    if (event->type() == EventTypeNames::message) {
+        v8::HandleScope handleScope(isolate());
+        StringBuilder scriptInfoBuilder;
+        V8StringResource<> functionName = handlerFunction->GetDebugName();
+        if (functionName.prepare()) {
+            scriptInfoBuilder.append(static_cast<String>(functionName));
+        }
+        scriptInfoBuilder.append(':');
+        scriptInfoBuilder.appendNumber(handlerFunction->GetScriptLineNumber());
+        scriptInfoBuilder.append(':');
+        scriptInfoBuilder.appendNumber(handlerFunction->GetScriptColumnNumber());
+        scriptInfoBuilder.append(':');
+        V8StringResource<> scriptName = handlerFunction->GetScriptOrigin().ResourceName();
+        if (scriptName.prepare()) {
+            scriptInfoBuilder.append(static_cast<String>(scriptName));
+        }
+        scriptInfo = scriptInfoBuilder.toString();
+    }
+    WTF::debug::ScopedCrashKey("postmessage_script_info", scriptInfo.utf8().data());
+
     v8::Local<v8::Value> parameters[1] = { jsEvent };
     v8::Local<v8::Value> result;
     if (!frame->script().callFunction(handlerFunction, receiver, WTF_ARRAY_LENGTH(parameters), parameters).ToLocal(&result))