Implement Virtual Display class for Android.

ui/android/java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java

Index: ui/android/java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java
diff --git a/ui/android/java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java b/ui/android/java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java
new file mode 100644
index 0000000000000000000000000000000000000000..964ef6fa99124e1507cab8c48e3537ab1c1664ec
--- /dev/null
+++ b/ui/android/java/src/org/chromium/ui/display/PhysicalDisplayAndroid.java
@@ -0,0 +1,113 @@
+// Copyright 2016 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.ui.display;
+
+import android.annotation.TargetApi;
+import android.graphics.PixelFormat;
+import android.graphics.Point;
+import android.os.Build;
+import android.util.DisplayMetrics;
+import android.view.Display;
+
+import org.chromium.base.CommandLine;
+import org.chromium.base.Log;
+
+/**
+ * A DisplayAndroid implementation tied to a physical Display.
+ */
+/* package */ class PhysicalDisplayAndroid extends DisplayAndroid {
+    private static final String TAG = "DisplayAndroid";
+
+    // When this object exists, a positive value means that the forced DIP scale is set and
+    // the zero means it is not. The non existing object (i.e. null reference) means that
+    // the existence and value of the forced DIP scale has not yet been determined.
+    private static Float sForcedDIPScale;
+
+    private static boolean hasForcedDIPScale() {
+        if (sForcedDIPScale == null) {
+            String forcedScaleAsString = CommandLine.getInstance().getSwitchValue(
+                    DisplaySwitches.FORCE_DEVICE_SCALE_FACTOR);
+            if (forcedScaleAsString == null) {
+                sForcedDIPScale = Float.valueOf(0.0f);
+            } else {
+                boolean isInvalid = false;
+                try {
+                    sForcedDIPScale = Float.valueOf(forcedScaleAsString);
+                    // Negative values are discarded.
+                    if (sForcedDIPScale.floatValue() <= 0.0f) isInvalid = true;
+                } catch (NumberFormatException e) {
+                    // Strings that do not represent numbers are discarded.
+                    isInvalid = true;
+                }
+
+                if (isInvalid) {
+                    Log.w(TAG, "Ignoring invalid forced DIP scale '" + forcedScaleAsString + "'");
+                    sForcedDIPScale = Float.valueOf(0.0f);
+                }
+            }
+        }
+        return sForcedDIPScale.floatValue() > 0;
+    }
+
+    @SuppressWarnings("deprecation")
+    private int bitsPerComponent(int pixelFormatId) {
+        switch (pixelFormatId) {
+            case PixelFormat.RGBA_4444:
+                return 4;
+
+            case PixelFormat.RGBA_5551:
+                return 5;
+
+            case PixelFormat.RGBA_8888:
+            case PixelFormat.RGBX_8888:
+            case PixelFormat.RGB_888:
+                return 8;
+
+            case PixelFormat.RGB_332:
+                return 2;
+
+            case PixelFormat.RGB_565:
+                return 5;
+
+            // Non-RGB formats.
+            case PixelFormat.A_8:
+            case PixelFormat.LA_88:
+            case PixelFormat.L_8:
+                return 0;
+
+            // Unknown format. Use 8 as a sensible default.
+            default:
+                return 8;
+        }
+    }
+
+    /* package */ PhysicalDisplayAndroid(Display display) {
+        super(display.getDisplayId());
+    }
+
+    @SuppressWarnings("deprecation")
+    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
+    /* package */ void updateFromDisplay(Display display) {
+        Point size = new Point();
+        Point physicalSize = new Point();
+        DisplayMetrics displayMetrics = new DisplayMetrics();
+        PixelFormat pixelFormat = new PixelFormat();
+        display.getSize(size);
+        display.getMetrics(displayMetrics);
+        if (hasForcedDIPScale()) displayMetrics.density = sForcedDIPScale.floatValue();
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+            display.getRealSize(physicalSize);
+        }
+
+        // JellyBean MR1 and later always uses RGBA_8888.
+        int pixelFormatId = (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1)
+                ? display.getPixelFormat()
+                : PixelFormat.RGBA_8888;
+        PixelFormat.getPixelFormatInfo(pixelFormatId, pixelFormat);
+        super.update(size, physicalSize, displayMetrics.density, pixelFormat.bitsPerPixel,
+                bitsPerComponent(pixelFormatId), display.getRotation());
+    }
+}