When possible, draw the toolbar shadow with the compositor

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java
index 6794f2b1f86eb1063cbf2ea8889bab265971f2bb..99fbef5e33ffc8318bb2e38855f8333a622fd458 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerDocument.java
@@ -133,6 +133,8 @@ public class LayoutManagerDocument extends LayoutManager
         // Initialize Layouts
         mStaticLayout.setTabModelSelector(selector, content);
 
+        mToolbarOverlay.setTabModelSelector(selector);
+
         // Initialize Contextual Search Panel
         mContextualSearchPanel.setManagementDelegate(contextualSearchDelegate);
 
@@ -260,10 +262,13 @@ public class LayoutManagerDocument extends LayoutManager
         String url = tab.getUrl();
         boolean isNativePage = url != null && url.startsWith(UrlConstants.CHROME_NATIVE_SCHEME);
         int themeColor = tab.getThemeColor();
+        boolean needsToolbarShadow = tab.getNativePage() == null
+                ? true : tab.getNativePage().needsToolbarShadow();
         boolean canUseLiveTexture =
                 tab.getContentViewCore() != null && !tab.isShowingSadTab() && !isNativePage;
-        boolean needsUpdate = layoutTab.initFromHost(tab.getBackgroundColor(), tab.shouldStall(),
-                canUseLiveTexture, themeColor, ColorUtils.getTextBoxColorForToolbarBackground(
+        boolean needsUpdate = layoutTab.initFromHost(needsToolbarShadow, tab.getBackgroundColor(),
+                tab.shouldStall(), canUseLiveTexture, themeColor,
+                ColorUtils.getTextBoxColorForToolbarBackground(
                                     mContext.getResources(), tab, themeColor),
                 ColorUtils.getTextBoxAlphaForToolbarBackground(tab));
         if (needsUpdate) requestUpdate();
@@ -276,7 +281,10 @@ public class LayoutManagerDocument extends LayoutManager
             boolean isTitleNeeded, float maxContentWidth, float maxContentHeight) {
         LayoutTab tab = mTabCache.get(id);
         if (tab == null) {
-            tab = new LayoutTab(id, incognito, mLastContentWidthDp, mLastContentHeightDp,
+            boolean isNative = false;
+            Tab realTab = getTabModelSelector().getTabById(id);
+            if (realTab != null) isNative = realTab.isNativePage();
+            tab = new LayoutTab(id, incognito, isNative, mLastContentWidthDp, mLastContentHeightDp,
                     showCloseButton, isTitleNeeded);
             mTabCache.put(id, tab);
         } else {