[Android WebView] Allow embedders to override text from scaling by system font scale.

android_webview/java/src/org/chromium/android_webview/AwSettings.java

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.android_webview;
 
 import android.content.Context;
 import android.content.pm.PackageManager;
 import android.os.Handler;
 import android.os.Message;
@@ skipping 70 matching lines @@
     private boolean mMediaPlaybackRequiresUserGesture = true;
     private String mDefaultVideoPosterURL;
     private float mInitialPageScalePercent = 0;
     private boolean mSpatialNavigationEnabled;  // Default depends on device features.
     private boolean mEnableSupportedHardwareAcceleratedFeatures = false;
 
     private final boolean mSupportLegacyQuirks;
 
     private final boolean mPasswordEchoEnabled;
 
-    // Font scale factor determined by Android system setting.
-    private final float mFontScale;
-
     // Not accessed by the native side.
     private boolean mBlockNetworkLoads;  // Default depends on permission of embedding APK.
     private boolean mAllowContentUrlAccess = true;
     private boolean mAllowFileUrlAccess = true;
     private int mCacheMode = WebSettings.LOAD_DEFAULT;
     private boolean mShouldFocusFirstNode = true;
     private boolean mGeolocationEnabled = true;
     private boolean mAutoCompleteEnabled = true;
     private boolean mSupportZoom = true;
     private boolean mBuiltInZoomControls = false;
@@ skipping 112 matching lines @@
             mDefaultTextEncoding = AwResource.getDefaultTextEncoding();
             mUserAgent = LazyDefaultUserAgent.sInstance;
 
             // Best-guess a sensible initial value based on the features supported on the device.
             mSpatialNavigationEnabled = !context.getPackageManager().hasSystemFeature(
                     PackageManager.FEATURE_TOUCHSCREEN);
 
             // Respect the system setting for password echoing.
             mPasswordEchoEnabled = Settings.System.getInt(context.getContentResolver(),
                     Settings.System.TEXT_SHOW_PASSWORD, 1) == 1;
-            mFontScale = context.getResources().getConfiguration().fontScale;
-            mTextSizePercent *= mFontScale;
+
+            // By default, scale the text size by the system font scale factor. Embedders
+            // may override this by invoking setTextZoom().
+            mTextSizePercent *= context.getResources().getConfiguration().fontScale;
 
             mSupportLegacyQuirks = supportsLegacyQuirks;
         }
         // Defer initializing the native side until a native WebContents instance is set.
     }
 
     @CalledByNative
     private void nativeAwSettingsGone(long nativeAwSettings) {
         assert mNativeAwSettings != 0 && mNativeAwSettings == nativeAwSettings;
         mNativeAwSettings = 0;
@@ skipping 316 matching lines @@
     private boolean getLoadWithOverviewModeLocked() {
         assert Thread.holdsLock(mAwSettingsLock);
         return mLoadWithOverviewMode;
     }
 
     /**
      * See {@link android.webkit.WebSettings#setTextZoom}.
      */
     public void setTextZoom(final int textZoom) {
         synchronized (mAwSettingsLock) {
-            int scaledTextZoomPercent = (int)(textZoom * mFontScale);
-            if (mTextSizePercent != scaledTextZoomPercent) {
-                mTextSizePercent = scaledTextZoomPercent;
+            if (mTextSizePercent != textZoom) {
+                mTextSizePercent = textZoom;
                 mEventHandler.updateWebkitPreferencesLocked();
             }
         }
     }
 
     /**
      * See {@link android.webkit.WebSettings#getTextZoom}.
      */
     public int getTextZoom() {
         synchronized (mAwSettingsLock) {
@@ skipping 920 matching lines @@
     private native void nativeUpdateInitialPageScaleLocked(long nativeAwSettings);
 
     private native void nativeUpdateUserAgentLocked(long nativeAwSettings);
 
     private native void nativeUpdateWebkitPreferencesLocked(long nativeAwSettings);
 
     private static native String nativeGetDefaultUserAgent();
 
     private native void nativeUpdateFormDataPreferencesLocked(long nativeAwSettings);
 }