Make WebView respond to device scale change

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index be34d7dcd57cad827f55dae5c70fc4d44f7cdb6f..e628cbc6b8c44810f60ca51e3c7f893a04147309 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -1128,6 +1128,15 @@ public class ContentViewCore implements AccessibilityStateChangeListener, Screen
     }
 
     /**
+     * Sets the device scale factor (maps DIP pixels to physical pixels).
+     */
+    public void setDeviceScaleFactor(float value) {
+        mRenderCoordinates.setDeviceScaleFactor(value);
+        if (mNativeContentViewCore == 0) return;
+        nativeSetDeviceScaleFactor(mNativeContentViewCore, value);
+    }
+
+    /**
      * @return Current page scale factor (maps CSS pixels to DIP pixels).
      */
     @VisibleForTesting
@@ -1643,6 +1652,28 @@ public class ContentViewCore implements AccessibilityStateChangeListener, Screen
         }
     }
 
+    /**
+     * Called when the view size change is accompanied by the size of the underlying surface change.
+     */
+    public void onBackingAndViewportSizeChanged(

[boliu, 2016/08/02 18:09:27]

if the above two methods needs to be merged, then just merge them, and fix all
the callsites in clank as well, don't add a new one

also I don't quite understand why they need to be merged (see other comment)

[Tima Vaisburd, 2016/08/16 00:21:01]

Removed this method for now.

+            int wPixPhys, int hPixPhys, int wPix, int hPix, int owPix, int ohPix) {
+        if (mPhysicalBackingWidthPix == wPixPhys && mPhysicalBackingHeightPix == hPixPhys
+                && getViewportWidthPix() == wPix && getViewportHeightPix() == hPix) {
+            return;
+        }
+
+        mPhysicalBackingWidthPix = wPixPhys;
+        mPhysicalBackingHeightPix = hPixPhys;
+        mViewportWidthPix = wPix;
+        mViewportHeightPix = hPix;
+
+        if (mNativeContentViewCore != 0) {
+            nativeWasResized(mNativeContentViewCore);
+        }
+
+        updateAfterSizeChanged();
+    }
+
     private void updateAfterSizeChanged() {
         mPopupZoomer.hide(false);
 
@@ -3484,6 +3515,8 @@ public class ContentViewCore implements AccessibilityStateChangeListener, Screen
 
     private native void nativeSetFocus(long nativeContentViewCoreImpl, boolean focused);
 
+    private native void nativeSetDeviceScaleFactor(long nativeContentViewCoreImpl, float value);
+
     private native void nativeSendOrientationChangeEvent(
             long nativeContentViewCoreImpl, int orientation);