Add an UMA histogram for WebUSB function calls.

third_party/WebKit/Source/modules/webusb/USB.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/webusb/USB.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/frame/UseCounter.h"
 #include "device/usb/public/interfaces/device.mojom-blink.h"
 #include "modules/EventTargetModules.h"
 #include "modules/webusb/USBConnectionEvent.h"
 #include "modules/webusb/USBDevice.h"
 #include "modules/webusb/USBDeviceFilter.h"
 #include "modules/webusb/USBDeviceRequestOptions.h"
 #include "platform/UserGestureIndicator.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/InterfaceProvider.h"
 #include "wtf/Functional.h"
@@ skipping 49 matching lines @@
 
 void USB::dispose()
 {
     // The pipe to this object must be closed when is marked unreachable to
     // prevent messages from being dispatched before lazy sweeping.
     m_clientBinding.Close();
 }
 
 ScriptPromise USB::getDevices(ScriptState* scriptState)
 {
+    ExecutionContext* executionContext = scriptState->getExecutionContext();
+    UseCounter::count(executionContext, UseCounter::UsbGetDevices);
+
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     if (!m_deviceManager) {
         resolver->reject(DOMException::create(NotSupportedError));
     } else {
         String errorMessage;
-        if (!scriptState->getExecutionContext()->isSecureContext(errorMessage)) {
+        if (!executionContext->isSecureContext(errorMessage)) {
             resolver->reject(DOMException::create(SecurityError, errorMessage));
         } else {
             m_deviceManagerRequests.add(resolver);
             m_deviceManager->GetDevices(nullptr, convertToBaseCallback(WTF::bind(&USB::onGetDevices, wrapPersistent(this), wrapPersistent(resolver))));
         }
     }
     return promise;
 }
 
 ScriptPromise USB::requestDevice(ScriptState* scriptState, const USBDeviceRequestOptions& options)
 {
+    ExecutionContext* executionContext = scriptState->getExecutionContext();
+    UseCounter::count(executionContext, UseCounter::UsbRequestDevice);
+
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
 
     if (!m_chooserService) {
-        LocalFrame* frame = getExecutionContext() ? toDocument(getExecutionContext())->frame() : nullptr;
+        LocalFrame* frame = executionContext->isDocument() ? toDocument(executionContext)->frame() : nullptr;
         if (!frame) {
             resolver->reject(DOMException::create(NotSupportedError));
             return promise;
         }
         frame->interfaceProvider()->getInterface(mojo::GetProxy(&m_chooserService));
         m_chooserService.set_connection_error_handler(convertToBaseCallback(WTF::bind(&USB::onChooserServiceConnectionError, wrapWeakPersistent(this))));
     }
 
     String errorMessage;
-    if (!scriptState->getExecutionContext()->isSecureContext(errorMessage)) {
+    if (!executionContext->isSecureContext(errorMessage)) {
         resolver->reject(DOMException::create(SecurityError, errorMessage));
     } else if (!UserGestureIndicator::consumeUserGesture()) {
         resolver->reject(DOMException::create(SecurityError, "Must be handling a user gesture to show a permission request."));
     } else {
         Vector<usb::DeviceFilterPtr> filters;
         if (options.hasFilters()) {
             filters.reserveCapacity(options.filters().size());
             for (const auto& filter : options.filters())
                 filters.append(convertDeviceFilter(filter));
         }
@@ skipping 103 matching lines @@
 DEFINE_TRACE(USB)
 {
     EventTargetWithInlineData::trace(visitor);
     ContextLifecycleObserver::trace(visitor);
     visitor->trace(m_deviceManagerRequests);
     visitor->trace(m_chooserServiceRequests);
     visitor->trace(m_deviceCache);
 }
 
 } // namespace blink