Make WebView work for external displays (over Presentations).

ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java

Index: ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
diff --git a/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java b/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
index da8e0262a1f9e202086b5d4095cc61b47555dd48..15ff695a5c1e72b06f5f2205ea6d78bcc245f595 100644
--- a/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
+++ b/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
@@ -16,6 +16,9 @@ import android.view.WindowManager;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
+import org.chromium.ui.base.WindowAndroid;
+
+import java.lang.ref.WeakReference;
 
 /**
  * This class facilitates access to android information typically only
@@ -27,14 +30,17 @@ import org.chromium.base.JNINamespace;
 @JNINamespace("gfx")
 public class DeviceDisplayInfo {
 
-    private final Context mAppContext;
+    private final WeakReference<Context> mContextRef;
     private final WindowManager mWinManager;
     private Point mTempPoint = new Point();
     private DisplayMetrics mTempMetrics = new DisplayMetrics();
 
-    private DeviceDisplayInfo(Context context) {
-        mAppContext = context.getApplicationContext();
-        mWinManager = (WindowManager) mAppContext.getSystemService(Context.WINDOW_SERVICE);
+    private DeviceDisplayInfo(WeakReference<Context> contextRef) {
+        mContextRef = contextRef;
+        Context context = mContextRef.get();
+        if (context == null)
+            throw new RuntimeException("got null Context in DeviceDisplayInfo constructor");
+        mWinManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
     }
 
     /**
@@ -154,7 +160,10 @@ public class DeviceDisplayInfo {
      */
     @CalledByNative
     private int getSmallestDIPWidth() {
-        return mAppContext.getResources().getConfiguration().smallestScreenWidthDp;
+        Context context = mContextRef.get();
+        if (context == null)
+            throw new RuntimeException("null context in getSmallestDIPWidth!!!");
+        return context.getResources().getConfiguration().smallestScreenWidthDp;
     }
 
     /**
@@ -181,18 +190,6 @@ public class DeviceDisplayInfo {
         return 0;
     }
 
-    /**
-     * Inform the native implementation to update its cached representation of
-     * the DeviceDisplayInfo values.
-     */
-    public void updateNativeSharedDisplayInfo() {
-        nativeUpdateSharedDeviceDisplayInfo(
-                getDisplayHeight(), getDisplayWidth(),
-                getPhysicalDisplayHeight(), getPhysicalDisplayWidth(),
-                getBitsPerPixel(), getBitsPerComponent(),
-                getDIPScale(), getSmallestDIPWidth(), getRotationDegrees());
-    }
-
     private Display getDisplay() {
         return mWinManager.getDefaultDisplay();
     }
@@ -204,14 +201,15 @@ public class DeviceDisplayInfo {
      * @return DeviceDisplayInfo associated with a given Context.
      */
     @CalledByNative
-    public static DeviceDisplayInfo create(Context context) {
-        return new DeviceDisplayInfo(context);
+    public static DeviceDisplayInfo createFromWindow(WindowAndroid windowAndroid) {
+        if (windowAndroid == null)
+            throw new RuntimeException("passed null windowAndroid to DeviceDisplayInfo.create");
+        return new DeviceDisplayInfo(windowAndroid.getCurrentContext());
     }
 
-    private native void nativeUpdateSharedDeviceDisplayInfo(
-            int displayHeight, int displayWidth,
-            int physicalDisplayHeight, int physicalDisplayWidth,
-            int bitsPerPixel, int bitsPerComponent, double dipScale,
-            int smallestDIPWidth, int rotationDegrees);
+    @CalledByNative
+    public static DeviceDisplayInfo create(Context context) { // TODO createFromContext
+        return new DeviceDisplayInfo(new WeakReference<Context>(context));
+    }
 
 }