Fix Android hit testing in a totally static page.

content/browser/accessibility/browser_accessibility_manager_android.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility_manager_android.h"
 
 #include <cmath>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 398 matching lines @@
 
 void BrowserAccessibilityManagerAndroid::HandleHoverEvent(
     BrowserAccessibility* node) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
   if (obj.is_null())
     return;
 
   BrowserAccessibilityAndroid* ancestor =
       static_cast<BrowserAccessibilityAndroid*>(node->GetParent());
-  while (ancestor) {
+  while (ancestor && ancestor != GetRoot()) {

[aboxhall, 2014/10/16 21:33:34]

Would it be worthwhile pulling the result of GetRoot() out into a local pointer
to avoid calling the method repeatedly?

[dmazzoni, 2014/10/16 21:47:24]

The compiler ought to be smart enough to do this. Still might be a good idea if
GetRoot was known to be expensive, just in case - but it's cheap so I think it's
more concise like this.

     if (ancestor->PlatformIsLeaf() ||
         (ancestor->IsFocusable() && !ancestor->HasFocusableChild())) {
       node = ancestor;
       // Don't break - we want the highest ancestor that's focusable or a
       // leaf node.
     }
     ancestor = static_cast<BrowserAccessibilityAndroid*>(ancestor->GetParent());
   }
 
   Java_BrowserAccessibilityManager_handleHover(
@@ skipping 70 matching lines @@
 BrowserAccessibilityManagerAndroid::UseRootScrollOffsetsWhenComputingBounds() {
   // The Java layer handles the root scroll offset.
   return false;
 }
 
 bool RegisterBrowserAccessibilityManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content