Implement Android accessible hit testing using an IPC to the renderer process.

content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java

Index: content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java b/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
index 63deca865b67ba0a772f2fce6225320f780b215b..6f4723369ce1bc00f9f45a8435c8beebc875c66f 100644
--- a/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
+++ b/content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
@@ -248,18 +248,12 @@ public class BrowserAccessibilityManager {
         float y = event.getY();
 
         // Convert to CSS coordinates.
-        int cssX = (int) (mRenderCoordinates.fromPixToLocalCss(x) +
-                          mRenderCoordinates.getScrollX());
-        int cssY = (int) (mRenderCoordinates.fromPixToLocalCss(y) +
-                          mRenderCoordinates.getScrollY());
-        int id = nativeHitTest(mNativeObj, cssX, cssY);
-        if (mLastHoverId != id) {
-            // Always send the ENTER and then the EXIT event, to match a standard Android View.
-            sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_HOVER_ENTER);
-            sendAccessibilityEvent(mLastHoverId, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT);
-            mLastHoverId = id;
-        }
+        int cssX = (int) (mRenderCoordinates.fromPixToLocalCss(x));
+        int cssY = (int) (mRenderCoordinates.fromPixToLocalCss(y));
 
+        // This sends an IPC to the render process to do the hit testing.
+        // The response is handled by handleHover.
+        nativeHitTest(mNativeObj, cssX, cssY);
         return true;
     }
 
@@ -441,6 +435,16 @@ public class BrowserAccessibilityManager {
     }
 
     @CalledByNative
+    private void handleHover(int id) {
+        if (mLastHoverId == id) return;
+
+        // Always send the ENTER and then the EXIT event, to match a standard Android View.
+        sendAccessibilityEvent(id, AccessibilityEvent.TYPE_VIEW_HOVER_ENTER);
+        sendAccessibilityEvent(mLastHoverId, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT);
+        mLastHoverId = id;
+    }
+
+    @CalledByNative
     private void announceLiveRegionText(String text) {
         mView.announceForAccessibility(text);
     }
@@ -682,7 +686,7 @@ public class BrowserAccessibilityManager {
 
     private native int nativeGetRootId(long nativeBrowserAccessibilityManagerAndroid);
     private native boolean nativeIsNodeValid(long nativeBrowserAccessibilityManagerAndroid, int id);
-    private native int nativeHitTest(long nativeBrowserAccessibilityManagerAndroid, int x, int y);
+    private native void nativeHitTest(long nativeBrowserAccessibilityManagerAndroid, int x, int y);
     private native boolean nativePopulateAccessibilityNodeInfo(
         long nativeBrowserAccessibilityManagerAndroid, AccessibilityNodeInfo info, int id);
     private native boolean nativePopulateAccessibilityEvent(