WebView: add support for MultiWindow when choosing interstitial

This CL changes the logic for choosing the loud vs. quiet interstitial.
Instead of comparing against screen dimensions, we instead use window
dimensions, which makes more sense when Android Multi-Window is enabled.

BUG=718195

Review-Url: https://codereview.chromium.org/2861713005
Cr-Commit-Position: refs/heads/master@{#469521}

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -80,7 +80,6 @@ import org.chromium.ui.base.ActivityWindowAndroid;
 import org.chromium.ui.base.PageTransition;
 import org.chromium.ui.base.ViewAndroidDelegate;
 import org.chromium.ui.base.WindowAndroid;
-import org.chromium.ui.display.DisplayAndroid;
 import org.chromium.ui.display.DisplayAndroid.DisplayAndroidObserver;
 
 import java.io.File;
@@ -120,7 +119,7 @@ public class AwContents implements SmartClipProvider {
     private static final boolean FORCE_AUXILIARY_BITMAP_RENDERING =
             "goldfish".equals(Build.HARDWARE) || "ranchu".equals(Build.HARDWARE);
 
-    private static final double MIN_SCREEN_PERCENTAGE_FOR_INTERSTITIAL = 0.7;
+    private static final double MIN_SCREEN_HEIGHT_PERCENTAGE_FOR_INTERSTITIAL = 0.7;
 
     /**
      * WebKit hit test related data structure. These are used to implement
@@ -2917,16 +2916,25 @@ public class AwContents implements SmartClipProvider {
     }
 
     /**
-     * Determine if at least one edge of the WebView extends over the edge of the device screen.
+     * Determine if at least one edge of the WebView extends over the edge of the window.
      */
-    private boolean extendsOffDeviceScreen() {
+    private boolean extendsOutOfWindow() {
         int loc[] = new int[2];
         mContainerView.getLocationOnScreen(loc);
         int x = loc[0];
         int y = loc[1];
-        DisplayAndroid displayAndroid = mWindowAndroid.getWindowAndroid().getDisplay();
-        if (x < 0 || y < 0 || x + mContainerView.getWidth() > displayAndroid.getDisplayWidth()
-                || y + mContainerView.getHeight() > displayAndroid.getDisplayHeight()) {
+        mContainerView.getRootView().getLocationOnScreen(loc);
+        int rootX = loc[0];
+        int rootY = loc[1];
+
+        // Get the position of the current view, relative to its root view
+        int relativeX = x - rootX;
+        int relativeY = y - rootY;
+
+        if (relativeX < 0 || relativeY < 0
+                || relativeX + mContainerView.getWidth() > mContainerView.getRootView().getWidth()
+                || relativeY + mContainerView.getHeight()
+                        > mContainerView.getRootView().getHeight()) {
             return true;
         }
         return false;
@@ -2953,15 +2961,14 @@ public class AwContents implements SmartClipProvider {
     @CalledByNative
     protected boolean canShowBigInterstitial() {
         if (!canShowInterstitial()) return false;
-        if (extendsOffDeviceScreen()) return false;
+        if (extendsOutOfWindow()) return false;
 
-        DisplayAndroid displayAndroid = mWindowAndroid.getWindowAndroid().getDisplay();
         double percentOfScreenHeight =
-                (double) mContainerView.getHeight() / displayAndroid.getDisplayHeight();
+                (double) mContainerView.getHeight() / mContainerView.getRootView().getHeight();
 
-        // If the WebView is full width and most of the height, it's probably the main UI.
-        return mContainerView.getWidth() == displayAndroid.getDisplayWidth()
-                && percentOfScreenHeight >= MIN_SCREEN_PERCENTAGE_FOR_INTERSTITIAL;
+        // Make a guess as to whether the WebView is the predominant part of the UI
+        return mContainerView.getWidth() == mContainerView.getRootView().getWidth()
+                && percentOfScreenHeight >= MIN_SCREEN_HEIGHT_PERCENTAGE_FOR_INTERSTITIAL;
     }
 
     @VisibleForTesting