Resize only the virtual viewport when the OSK triggers a resize.

chrome/android/java/src/org/chromium/chrome/browser/InsetObserverView.java

Index: chrome/android/java/src/org/chromium/chrome/browser/InsetObserverView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/InsetObserverView.java b/chrome/android/java/src/org/chromium/chrome/browser/InsetObserverView.java
new file mode 100644
index 0000000000000000000000000000000000000000..8e2142a40ed408aabf1dfcd7cb778522ea03c484
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/InsetObserverView.java
@@ -0,0 +1,103 @@
+// 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.chrome.browser;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.graphics.Rect;
+import android.os.Build;
+import android.view.View;
+import android.view.WindowInsets;
+
+/**
+ * The purpose of this view is to store the system window insets (OSK, status bar) for
+ * later use.
+ */
+public class InsetObserverView extends View {
+
+    protected final Rect mWindowInsets;
+
+    /**
+     * Constructs a new {@link InsetObserverView} for the appropriate Android version.
+     * @param context The Context the view is running in, through which it can access the current
+     *            theme, resources, etc.
+     * @return an instance of a InsetObserverView.
+     */
+    public static InsetObserverView create(Context context) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            return new InsetObserverView(context);
+        }
+        return new InsetObserverViewApi21(context);
+    }
+
+    /**
+     * Creates an instance of {@link InsetObserverView}.
+     * @param context The Context to create this {@link InsetObserverView} in.
+     */
+    public InsetObserverView(Context context) {
+        super(context);
+        setVisibility(INVISIBLE);
+        mWindowInsets = new Rect();
+    }
+
+    /**
+     * Returns the left {@link WindowInsets} in pixels.
+     */
+    public int getSystemWindowInsetsLeft() {
+        return mWindowInsets.left;
+    }
+
+    /**
+     * Returns the top {@link WindowInsets} in pixels.
+     */
+    public int getSystemWindowInsetsTop() {
+        return mWindowInsets.top;
+    }
+
+    /**
+     * Returns the right {@link WindowInsets} in pixels.
+     */
+    public int getSystemWindowInsetsRight() {
+        return mWindowInsets.right;
+    }
+
+    /**
+     * Returns the bottom {@link WindowInsets} in pixels.
+     */
+    public int getSystemWindowInsetsBottom() {
+        return mWindowInsets.bottom;
+    }
+
+    @SuppressWarnings("deprecation")
+    @Override
+    protected boolean fitSystemWindows(Rect insets) {
+        // For Lollipop and above, onApplyWindowInsets will set the insets.
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            mWindowInsets.set(insets.left, insets.top, insets.right, insets.bottom);
+        }
+        return false;
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static class InsetObserverViewApi21 extends InsetObserverView {
+        /**
+         * Creates an instance of {@link InsetObserverView} for Android versions L and above.
+         * @param context The Context to create this {@link InsetObserverView} in.
+         */
+        InsetObserverViewApi21(Context context) {
+            super(context);
+        }
+
+        @Override
+        public WindowInsets onApplyWindowInsets(WindowInsets insets) {
+            mWindowInsets.set(
+                    insets.getSystemWindowInsetLeft(),
+                    insets.getSystemWindowInsetTop(),
+                    insets.getSystemWindowInsetRight(),
+                    insets.getSystemWindowInsetBottom());
+            return insets;
+        }
+    }
+}