Add text autosizing override in the inspector.

Source/core/page/Settings.h

Index: Source/core/page/Settings.h
diff --git a/Source/core/page/Settings.h b/Source/core/page/Settings.h
index 25be2dd89357246cf7dc8703408a3f25836c6dae..78bdd7ceb1f7e8bf5bee4152085f213882f730c2 100644
--- a/Source/core/page/Settings.h
+++ b/Source/core/page/Settings.h
@@ -48,6 +48,12 @@ enum EditableLinkBehavior {
     EditableLinkNeverLive
 };
 
+enum TextAutosizingOverride {
+    NoOverride,
+    TextAutosizingOverrideEnabled,
+    TextAutosizingOverrideDisabled
+};
+
 // UScriptCode uses -1 and 0 for UScriptInvalidCode and UScriptCommon.
 // We need to use -2 and -3 for empty value and deleted value.
 struct UScriptCodeHashTraits : WTF::GenericHashTraits<int> {
@@ -86,7 +92,7 @@ public:
     const AtomicString& pictographFontFamily(UScriptCode = USCRIPT_COMMON) const;
 
     void setTextAutosizingEnabled(bool);
-    bool textAutosizingEnabled() const { return m_textAutosizingEnabled; }
+    bool textAutosizingEnabled() const;
 
     void setTextAutosizingFontScaleFactor(float);
     float textAutosizingFontScaleFactor() const { return m_textAutosizingFontScaleFactor; }
@@ -95,6 +101,8 @@ public:
     void setTextAutosizingWindowSizeOverride(const IntSize&);
     const IntSize& textAutosizingWindowSizeOverride() const { return m_textAutosizingWindowSizeOverride; }
 
+    void setTextAutosizingEnabledOverride(TextAutosizingOverride);
+
     void setUseWideViewport(bool);
     bool useWideViewport() const { return m_useWideViewport; }
 
@@ -175,6 +183,7 @@ private:
     bool m_textAutosizingEnabled : 1;
     bool m_useWideViewport : 1;
     bool m_loadWithOverviewMode : 1;
+    unsigned m_textAutosizingOverride : 2; // TextAutosizingOverride
 
     SETTINGS_MEMBER_VARIABLES