Move inverted mode to Accessibility settings
Add contrast settings

bug:5111259

Change-Id: Ic95e1fbae94c01fc8560cbd326503244b9ab4988
diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index 35393ac..11972ee 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -250,8 +250,11 @@
             settings.setUserAgentString(USER_AGENTS[getUserAgent()]);
         }
 
-        settings.setProperty("gfxInvertedScreen",
+        settings.setProperty(PREF_INVERTED,
                 useInvertedRendering() ? "true" : "false");
+
+        settings.setProperty(PREF_INVERTED_CONTRAST,
+                Float.toString(getInvertedContrast()));
     }
 
     /**
@@ -735,6 +738,14 @@
         return mPrefs.getBoolean(PREF_INVERTED, false);
     }
 
+    public float getInvertedContrast() {
+        return 1 + (mPrefs.getInt(PREF_INVERTED_CONTRAST, 0) / 10f);
+    }
+
+    public void setInvertedContrast(int contrast) {
+        mPrefs.edit().putInt(PREF_INVERTED_CONTRAST, contrast).apply();
+    }
+
     // -----------------------------
     // getter/setters for privacy_security_preferences.xml
     // -----------------------------