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..c6aa5cd0045a951bfbe82494f53425bb61a27757 100644
--- a/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
+++ b/ui/android/java/src/org/chromium/ui/gfx/DeviceDisplayInfo.java
@@ -17,6 +17,8 @@ import android.view.WindowManager;
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 
+import java.lang.ref.WeakReference;
+
 /**
  * This class facilitates access to android information typically only
  * available using the Java SDK, including {@link Display} properties.
@@ -26,15 +28,16 @@ import org.chromium.base.JNINamespace;
  */
 @JNINamespace("gfx")
 public class DeviceDisplayInfo {
-
-    private final Context mAppContext;
+    private final WeakReference<Context> mContextRef;
     private final WindowManager mWinManager;
+    private final int mSmallestDIPWidth;
     private Point mTempPoint = new Point();
     private DisplayMetrics mTempMetrics = new DisplayMetrics();
 
     private DeviceDisplayInfo(Context context) {
-        mAppContext = context.getApplicationContext();
-        mWinManager = (WindowManager) mAppContext.getSystemService(Context.WINDOW_SERVICE);
+        mContextRef = new WeakReference<Context>(context);
+        mWinManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        mSmallestDIPWidth = context.getResources().getConfiguration().smallestScreenWidthDp;
     }
 
     /**
@@ -153,8 +156,8 @@ public class DeviceDisplayInfo {
      *         application will see, regardless of orientation.
      */
     @CalledByNative
-    private int getSmallestDIPWidth() {
-        return mAppContext.getResources().getConfiguration().smallestScreenWidthDp;
+    private int getSmallestDIPWidth() { // TODO(gsennton) can we remove this?
+        return mSmallestDIPWidth;
     }
 
     /**
@@ -181,18 +184,6 @@ 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();
     }
@@ -207,11 +198,4 @@ public class DeviceDisplayInfo {
     public static DeviceDisplayInfo create(Context context) {
         return new DeviceDisplayInfo(context);
     }
-
-    private native void nativeUpdateSharedDeviceDisplayInfo(
-            int displayHeight, int displayWidth,
-            int physicalDisplayHeight, int physicalDisplayWidth,
-            int bitsPerPixel, int bitsPerComponent, double dipScale,
-            int smallestDIPWidth, int rotationDegrees);
-
 }