Implement quota estimation API from Storage spec

third_party/WebKit/Source/modules/modules.gypi

 {
   'includes': [
     '../core/core_generated.gypi',
     'modules_generated.gypi',
   ],
   'variables': {
     # Experimental hooks for embedder to provide extra IDL and source files.
     #
     # Note: this is not a supported API. If you rely on this, you will be broken
     # from time to time as the code generator changes in backward incompatible
@@ skipping 499 matching lines @@
       'payments/PaymentOptions.idl',
       'payments/PaymentItem.idl',
       'payments/ShippingOption.idl',
       'permissions/MidiPermissionDescriptor.idl',
       'permissions/PermissionDescriptor.idl',
       'permissions/PushPermissionDescriptor.idl',
       'presentation/PresentationConnectionAvailableEventInit.idl',
       'presentation/PresentationConnectionCloseEventInit.idl',
       'push_messaging/PushEventInit.idl',
       'push_messaging/PushSubscriptionOptions.idl',
+      'quota/StorageEstimate.idl',
       'serviceworkers/ClientQueryOptions.idl',
       'serviceworkers/ExtendableEventInit.idl',
       'serviceworkers/ExtendableMessageEventInit.idl',
       'serviceworkers/FetchEventInit.idl',
       'serviceworkers/ForeignFetchEventInit.idl',
       'serviceworkers/ForeignFetchOptions.idl',
       'serviceworkers/ForeignFetchResponse.idl',
       'serviceworkers/RegistrationOptions.idl',
       'serviceworkers/ServiceWorkerMessageEventInit.idl',
       'speech/SpeechRecognitionErrorInit.idl',
@@ skipping 152 matching lines @@
       '<(blink_modules_output_dir)/permissions/PushPermissionDescriptor.cpp',
       '<(blink_modules_output_dir)/permissions/PushPermissionDescriptor.h',
       '<(blink_modules_output_dir)/presentation/PresentationConnectionAvailableEventInit.cpp',
       '<(blink_modules_output_dir)/presentation/PresentationConnectionAvailableEventInit.h',
       '<(blink_modules_output_dir)/presentation/PresentationConnectionCloseEventInit.cpp',
       '<(blink_modules_output_dir)/presentation/PresentationConnectionCloseEventInit.h',
       '<(blink_modules_output_dir)/push_messaging/PushEventInit.cpp',
       '<(blink_modules_output_dir)/push_messaging/PushEventInit.h',
       '<(blink_modules_output_dir)/push_messaging/PushSubscriptionOptions.cpp',
       '<(blink_modules_output_dir)/push_messaging/PushSubscriptionOptions.h',
+      '<(blink_modules_output_dir)/quota/StorageEstimate.cpp',
+      '<(blink_modules_output_dir)/quota/StorageEstimate.h',
       '<(blink_modules_output_dir)/serviceworkers/ClientQueryOptions.cpp',
       '<(blink_modules_output_dir)/serviceworkers/ClientQueryOptions.h',
       '<(blink_modules_output_dir)/serviceworkers/ExtendableEventInit.cpp',
       '<(blink_modules_output_dir)/serviceworkers/ExtendableEventInit.h',
       '<(blink_modules_output_dir)/serviceworkers/ExtendableMessageEventInit.cpp',
       '<(blink_modules_output_dir)/serviceworkers/ExtendableMessageEventInit.h',
       '<(blink_modules_output_dir)/serviceworkers/FetchEventInit.cpp',
       '<(blink_modules_output_dir)/serviceworkers/FetchEventInit.h',
       '<(blink_modules_output_dir)/serviceworkers/ForeignFetchEventInit.cpp',
       '<(blink_modules_output_dir)/serviceworkers/ForeignFetchEventInit.h',
@@ skipping 1307 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }