Block "setMediaOverridesForTesting" media IPC endpoints when not test…

…ing and instead reset values

https://bugs.webkit.org/show_bug.cgi?id=268731
rdar://122218365

Reviewed by Youenn Fablet.

The fix in https://commits.webkit.org/272448.445@safari-7618-branch was insufficient as
the setMediaOverridesForTesting IPC endpoints is also used to reset the flags to their default.

So rather than disabling the IPC endpoints altogether we restrict its use to only reset
the default values (which are all unset).

* Source/WebKit/GPUProcess/GPUConnectionToWebProcess.cpp:
(WebKit::GPUConnectionToWebProcess::setMediaOverridesForTesting):
* Source/WebKit/GPUProcess/GPUConnectionToWebProcess.messages.in:

Originally-landed-as: 272448.473@safari-7618-branch (00b3f3c). rdar://124557967
Canonical link: https://commits.webkit.org/276185@main

Source/WebKit/GPUProcess/GPUConnectionToWebProcess.cpp

@@ -838,6 +838,16 @@ void GPUConnectionToWebProcess::releaseRemoteCommandListener(RemoteRemoteCommand
 
 void GPUConnectionToWebProcess::setMediaOverridesForTesting(MediaOverridesForTesting overrides)
 {
+    if (!allowTestOnlyIPC()) {
+        MESSAGE_CHECK(!overrides.systemHasAC && !overrides.systemHasBattery && !overrides.vp9HardwareDecoderDisabled && !overrides.vp9DecoderDisabled && !overrides.vp9ScreenSizeAndScale);
+#if PLATFORM(COCOA)
+#if ENABLE(VP9)
+        VP9TestingOverrides::singleton().resetOverridesToDefaultValues();
+#endif
+        SystemBatteryStatusTestingOverrides::singleton().resetOverridesToDefaultValues();
+#endif
+        return;
+    }
 #if ENABLE(VP9) && PLATFORM(COCOA)
     VP9TestingOverrides::singleton().setHardwareDecoderDisabled(WTFMove(overrides.vp9HardwareDecoderDisabled));
     VP9TestingOverrides::singleton().setVP9DecoderDisabled(WTFMove(overrides.vp9DecoderDisabled));