Searching for "PrivateScript" reveals lots of it:

https://cs.chromium.org/search/?q=PrivateScript+file:webkit&p=2&sq=package:chromium&type=cs

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7b2c60e1df2e57cec4407b975b998af213f29c50

commit 7b2c60e1df2e57cec4407b975b998af213f29c50
Author: adithyas <adithyas@chromium.org>
Date: Wed Dec 14 04:40:27 2016

Remove Blink-in-JS

Things removed:

- PrivateScriptRunner(.h|.cpp|.js)
- PrivateScriptTest*
- ImplementedInPrivateScript, OnlyExposedToPrivateScript, NoImplHeader idl attributes
- ExposeConfiguration enum in V8DOMConfiguration
- PrivateScriptIsolatedWorldId and DOMWrapperWorld::getPrivateScriptIsolatedWorld()
- UseCounter::countIfNotPrivateScript and Deprecation::countDeprecationIfNotPrivateScript

BUG= 673844 

Review-Url: https://codereview.chromium.org/2571063002
Cr-Commit-Position: refs/heads/master@{#438432}

[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/content/child/blink_platform_impl.cc
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/LayoutTests/TestExpectations
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/LayoutTests/fast/dom/private_script_unittest-expected.txt
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/LayoutTests/fast/dom/private_script_unittest.html
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/IDLExtendedAttributes.md
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/IDLExtendedAttributes.txt
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/bindings.gni
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.h
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/bindings/core/v8/PrivateScriptRunner.cpp
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/bindings/core/v8/PrivateScriptRunner.h
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/bindings/core/v8/PrivateScriptRunner.js
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/ScriptController.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8NodeFilterCondition.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8PerContextData.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/V8PerContextData.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/custom/V8DocumentCustom.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/custom/V8EventTargetCustom.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLAllCollectionCustom.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLPlugInElementCustom.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/code_generator_v8.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/compute_interfaces_info_individual.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/compute_interfaces_info_overall.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/v8_attributes.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/v8_interface.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/v8_methods.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/v8_types.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/scripts/v8_utilities.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/attributes.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/constants.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/interface.h.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/idls/core/TestInterface3.idl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/idls/core/TestInterfacePartial.idl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/idls/core/TestObject.idl
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8SVGTestInterface.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestCallbackFunctions.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestConstants.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestDictionary.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestException.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestIntegerIndexed.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestIntegerIndexedGlobal.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestIntegerIndexedPrimaryGlobal.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface2.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface3.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterface3.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCheckSecurity.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceConstructor.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceDocument.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceEventInitConstructor.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceGarbageCollected.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceNamedConstructor.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceNode.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceOriginTrialEnabled.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceSecureContext.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestNode.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestObject.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestObject.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestSpecialOperations.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/core/V8TestTypedefs.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/modules/V8TestInterface2Partial.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/modules/V8TestInterface5.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/bindings/tests/results/modules/V8TestInterfacePartial.cpp
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/build/scripts/make_private_script_source.py
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/BUILD.gn
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/core_idl_files.gni
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/dom/ExceptionCode.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/frame/Deprecation.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/frame/Deprecation.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/frame/UseCounter.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/frame/UseCounter.h
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/testing/Internals.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/Source/core/testing/Internals.idl
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PartialPrivateScriptTest.idl
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PartialPrivateScriptTest.js
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PrivateScriptTest.cpp
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PrivateScriptTest.h
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PrivateScriptTest.idl
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PrivateScriptTest.js
[delete] https://crrev.com/f5df1e3fe0001e776729dafe7be76ad9f8096868/third_party/WebKit/Source/core/testing/PrivateScriptTestTest.cpp
[modify] https://crrev.com/7b2c60e1df2e57cec4407b975b998af213f29c50/third_party/WebKit/public/blink_resources.grd

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6414a1533148a728cd1c701a81b07abdc93f87da

commit 6414a1533148a728cd1c701a81b07abdc93f87da
Author: adithyas <adithyas@chromium.org>
Date: Fri Dec 16 03:55:13 2016

Remove some more private script related things

I missed out on removing a few things in http://crrev.com/2571063002, which I've cleaned up here.

BUG= 673844 

Review-Url: https://codereview.chromium.org/2576753002
Cr-Commit-Position: refs/heads/master@{#439011}

[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/content/child/blink_platform_impl.cc
[delete] https://crrev.com/f6fddd7fab5cf706023fc4f2edbdfa4fdd93d56f/third_party/WebKit/LayoutTests/fast/dom/marquee-named-property-crash.html
[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h
[delete] https://crrev.com/f6fddd7fab5cf706023fc4f2edbdfa4fdd93d56f/third_party/WebKit/Source/core/editing/js/DocumentExecCommand.js
[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/third_party/WebKit/Source/core/testing/Internals.h
[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/third_party/WebKit/Source/devtools/front_end/main/Main.js
[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js
[modify] https://crrev.com/6414a1533148a728cd1c701a81b07abdc93f87da/third_party/WebKit/public/blink_resources.grd