Cherry-pick bd0c3f3. rdar://113230434

    [visionOS] Under thermal throttling Safari webpage went blank when navigating
    https://bugs.webkit.org/show_bug.cgi?id=261374
    <radar://113230434>

    Reviewed by Dean Jackson.

    When the system is throttled due to thermal pressure, we can easily hit process
    timeouts and then web pages will fail to load.

    * Source/WebKit/UIProcess/AuxiliaryProcessProxy.cpp:
    (WebKit::adjustedTimeoutForThermalState):
    (WebKit::AuxiliaryProcessProxy::AuxiliaryProcessProxy):
    Query if thermal mitigation is enabled and increase process timeout if so.

    * Source/WebCore/platform/ThermalMitigationNotifier.cpp:
    (WebCore::ThermalMitigationNotifier::isThermalMitigationEnabled):
    Default implementation.

    * Source/WebCore/platform/ThermalMitigationNotifier.h:
    * Source/WebCore/platform/cocoa/ThermalMitigationNotifier.mm:
    (WebCore::isThermalMitigationEnabled):
    (-[WebThermalMitigationObserver thermalMitigationEnabled]):
    (WebCore::ThermalMitigationNotifier::isThermalMitigationEnabled):
    Add static member function to query if thermal mitigation is enabled
    as we don't need an instance function in AuxiliaryProcessProxy

    * Source/WebCore/WebCore.xcodeproj/project.pbxproj:
    Make ThermalMitigationNotifier.h a private header.

    Canonical link: https://commits.webkit.org/268149@main
Identifier: 265423.1038@safari-7616-branch

Source/WebCore/WebCore.xcodeproj/project.pbxproj

@@ -299,6 +299,7 @@
 		0BE030A20F3112FB003C1A46 /* RenderLineBoxList.h in Headers */ = {isa = PBXBuildFile; fileRef = 0BE030A10F3112FB003C1A46 /* RenderLineBoxList.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0C3F1F5B10C8871200D72CE1 /* WebGLUniformLocation.h in Headers */ = {isa = PBXBuildFile; fileRef = 0C3F1F5810C8871200D72CE1 /* WebGLUniformLocation.h */; };
 		0C45342810CDBBFA00869157 /* JSWebGLUniformLocation.h in Headers */ = {isa = PBXBuildFile; fileRef = 0C45342610CDBBFA00869157 /* JSWebGLUniformLocation.h */; };
+		0D44C33E2ABA1B9F0017FB5D /* ThermalMitigationNotifier.h in Headers */ = {isa = PBXBuildFile; fileRef = 2D8EF8122A9D511F000118F8 /* ThermalMitigationNotifier.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0E7058F41BC5CEDA0045A507 /* SearchPopupMenuCocoa.h in Headers */ = {isa = PBXBuildFile; fileRef = 0E7058F31BC5CCD70045A507 /* SearchPopupMenuCocoa.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0E9C1157291C18A400A2C2F2 /* ScreenDataOverrides.h in Headers */ = {isa = PBXBuildFile; fileRef = 0E9C1155291BF3CC00A2C2F2 /* ScreenDataOverrides.h */; settings = {ATTRIBUTES = (Private, ); }; };
 		0F03C0741884695E00A5F8CA /* SystemMemory.h in Headers */ = {isa = PBXBuildFile; fileRef = 0F03C0731884695E00A5F8CA /* SystemMemory.h */; };
@@ -41252,6 +41253,7 @@
 				44C9919F0F3D210E00586670 /* ThemeIOS.h in Headers */,
 				BCE659E60EA92FB2007E4533 /* ThemeMac.h in Headers */,
 				BCE659A90EA927B9007E4533 /* ThemeTypes.h in Headers */,
+				0D44C33E2ABA1B9F0017FB5D /* ThermalMitigationNotifier.h in Headers */,
 				976D6C95122B8A3D001FD1F7 /* ThreadableBlobRegistry.h in Headers */,
 				0B90561B0F2578BF0095FF6A /* ThreadableLoader.h in Headers */,
 				0B90561C0F2578BF0095FF6A /* ThreadableLoaderClient.h in Headers */,

Source/WebCore/platform/ThermalMitigationNotifier.cpp

@@ -41,6 +41,11 @@ bool ThermalMitigationNotifier::thermalMitigationEnabled() const
     return false;
 }
 
+bool ThermalMitigationNotifier::isThermalMitigationEnabled()
+{
+    return false;
+}
+
 #endif
 
 } // namespace WebCore

Source/WebCore/platform/ThermalMitigationNotifier.h

@@ -43,6 +43,7 @@ class ThermalMitigationNotifier : public CanMakeWeakPtr<ThermalMitigationNotifie
     WEBCORE_EXPORT ~ThermalMitigationNotifier();
 
     WEBCORE_EXPORT bool thermalMitigationEnabled() const;
+    WEBCORE_EXPORT static bool isThermalMitigationEnabled();
 
 private:
 #if HAVE(APPLE_THERMAL_MITIGATION_SUPPORT)

Source/WebCore/platform/cocoa/ThermalMitigationNotifier.mm

@@ -32,6 +32,13 @@
 #import <Foundation/NSProcessInfo.h>
 #import <wtf/MainThread.h>
 
+namespace WebCore {
+static bool isThermalMitigationEnabled()
+{
+    return NSProcessInfo.processInfo.thermalState >= NSProcessInfoThermalStateSerious;
+}
+}
+
 @interface WebThermalMitigationObserver : NSObject
 @property (nonatomic) WeakPtr<WebCore::ThermalMitigationNotifier> notifier;
 @property (nonatomic, readonly) BOOL thermalMitigationEnabled;
@@ -66,7 +73,7 @@ - (void)thermalStateDidChange
 
 - (BOOL)thermalMitigationEnabled
 {
-    return NSProcessInfo.processInfo.thermalState >= NSProcessInfoThermalStateSerious;
+    return WebCore::isThermalMitigationEnabled();
 }
 
 @end
@@ -89,6 +96,11 @@ - (BOOL)thermalMitigationEnabled
     return [m_observer thermalMitigationEnabled];
 }
 
+bool ThermalMitigationNotifier::isThermalMitigationEnabled()
+{
+    return WebCore::isThermalMitigationEnabled();
+}
+
 void ThermalMitigationNotifier::notifyThermalMitigationChanged(bool enabled)
 {
     m_callback(enabled);

Source/WebKit/UIProcess/AuxiliaryProcessProxy.cpp

@@ -44,10 +44,23 @@
 #import <pal/spi/ios/MobileGestaltSPI.h>
 #endif
 
+#if PLATFORM(VISION)
+#import <WebCore/ThermalMitigationNotifier.h>
+#endif
+
 namespace WebKit {
 
+static Seconds adjustedTimeoutForThermalState(Seconds timeout)
+{
+#if PLATFORM(VISION)
+    return WebCore::ThermalMitigationNotifier::isThermalMitigationEnabled() ? (timeout * 20) : timeout;
+#else
+    return timeout;
+#endif
+}
+
 AuxiliaryProcessProxy::AuxiliaryProcessProxy(bool alwaysRunsAtBackgroundPriority, Seconds responsivenessTimeout)
-    : m_responsivenessTimer(*this, responsivenessTimeout)
+    : m_responsivenessTimer(*this, adjustedTimeoutForThermalState(responsivenessTimeout))
     , m_alwaysRunsAtBackgroundPriority(alwaysRunsAtBackgroundPriority)
 #if USE(RUNNINGBOARD)
     , m_timedActivityForIPC(3_s)