r0hit0303
483a4fbd26
This change adds a dedicated `WebGLExtensionHandler` handler to handle farbling around WebGL's `getSupportedExtensions` and `getExtension` calls. The handler is instantiated taking into account different levels of fingerprinting protections as follows: #### 1) Balanced fingerprinting protections: - [WebGLBalancedFingerprintingProtection](https://sourcegraph.com/r/github.com/brave/brave-core/-/blob/chromium_src/third_party/blink/common/features.cc?L63) **enabled**: calls to `getSupportedExtensions` will injects a fake extension to the list and will keep this new list consistent till the lifetime of that handler. Calls to getExtension on the fake extension would return a fake `ScriptObject` with the name of the fake extension in CamelCase. - [WebGLBalancedFingerprintingProtection](https://sourcegraph.com/r/github.com/brave/brave-core/-/blob/chromium_src/third_party/blink/common/features.cc?L63) **disabled**: No change in behaviour i.e we don't farble and return the true list of supported extensions. #### 2) Maximum fingerprinting protections: - No change in behaviour i.e we continue to return a single entry for the getSupportedExtensions call viz. WEBGL_debug_renderer_info. #### 3) No fingerprinting protections: - No change in behaviour. We return the true list of supported extensions. Please note that this is part of the change from the bigger [PR](https://github.com/brave/brave-core/pull/36605). The `WebGLExtensionHandler` would later be created by [BraveSessionCache](https://sourcegraph.com/r/github.com/brave/brave-core/-/blob/third_party/blink/renderer/core/farbling/brave_session_cache.h). This integration with `BraveSessionCache` and then with `WebGLRenderingContextBase` would be followed in later CLs. This change also adds unit_tests for the same. Browser tests would be followed up later once we have the full integration complete. <!-- Add brave-browser issue below that this PR will resolve --> Related https://github.com/brave/brave-browser/issues/55858