[Modularization] Remove call to InfoBar#getNativeInfoBarPtr from InfoBarContainer

InfoBar#getNativeInfoBarPtr shouldn't be exposed in general. In this
case it was only used to get to top infobar's identifier. Replacing the
call with more targeted method.

BUG=1056346
R=mdjones@chromium.org

Change-Id: Ia2115a44a4badf5eec93ed858a49fa9bc7688c78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2108918Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Pavel Yatsuk <pavely@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751511}

chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainer.java

@@ -390,13 +390,13 @@ public class InfoBarContainer implements UserData, KeyboardVisibilityListener, I
     }
 
     /**
-     * @return Pointer to the native InfoBarAndroid object which is currently at the top of the
-     *         infobar stack, or 0 if there are no infobars.
+     * @return InfoBarIdentifier of the InfoBar which is currently at the top of the infobar stack,
+     *         or InfoBarIdentifier.INVALID if there are no infobars.
      */
     @CalledByNative
-    private long getTopNativeInfoBarPtr() {
-        if (!hasInfoBars()) return 0;
-        return mInfoBars.get(0).getNativeInfoBarPtr();
+    private @InfoBarIdentifier int getTopInfoBarIdentifier() {
+        if (!hasInfoBars()) return InfoBarIdentifier.INVALID;
+        return mInfoBars.get(0).getInfoBarIdentifier();
     }
 
     /**

chrome/browser/ui/android/infobars/infobar_container_android.cc

@@ -68,13 +68,12 @@ void InfoBarContainerAndroid::AttachJavaInfoBar(InfoBarAndroid* android_bar) {
           env, weak_java_infobar_container_.get(env))) {
     base::UmaHistogramSparse("InfoBar.Shown.Hidden",
                              android_bar->delegate()->GetIdentifier());
-    uintptr_t native_ptr = Java_InfoBarContainer_getTopNativeInfoBarPtr(
-        env, weak_java_infobar_container_.get(env));
-    if (native_ptr) {
-      base::UmaHistogramSparse("InfoBar.Shown.Hiding",
-                               reinterpret_cast<InfoBarAndroid*>(native_ptr)
-                                   ->delegate()
-                                   ->GetIdentifier());
+    infobars::InfoBarDelegate::InfoBarIdentifier identifier =
+        static_cast<infobars::InfoBarDelegate::InfoBarIdentifier>(
+            Java_InfoBarContainer_getTopInfoBarIdentifier(
+                env, weak_java_infobar_container_.get(env)));
+    if (identifier != infobars::InfoBarDelegate::InfoBarIdentifier::INVALID) {
+      base::UmaHistogramSparse("InfoBar.Shown.Hiding", identifier);
     }
   } else {
     base::UmaHistogramSparse("InfoBar.Shown.Visible",