When possible, draw the toolbar shadow with the compositor

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
index b5c41b85f737337db260541c8376243f7baf1a8c..37e2fbed09f242fe337e7787b54edc1ac02f4862 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/components/LayoutTab.java
@@ -68,6 +68,8 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
 
     private final int mId;
     private final boolean mIsIncognito;
+    private final boolean mIsNative;
+    private boolean mNeedsToolbarShadow;
 
     // Fields initialized in init()
     private float mScale;
@@ -146,6 +148,7 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      *
      * @param tabId                   The id of the source {@link Tab}.
      * @param isIncognito             Whether the tab in the in the incognito stack.
+     * @param isNative                Whether the tab a native page.
      * @param maxContentTextureWidth  The maximum width for drawing the content.
      * @param maxContentTextureHeight The maximum height for drawing the content.
      * @param showCloseButton         Whether a close button should be displayed in the corner.
@@ -153,10 +156,11 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      *                                optimization to save cycles and memory. This is
      *                                ignored if the title texture is already set.
      */
-    public LayoutTab(int tabId, boolean isIncognito, float maxContentTextureWidth,
+    public LayoutTab(int tabId, boolean isIncognito, boolean isNative, float maxContentTextureWidth,
             float maxContentTextureHeight, boolean showCloseButton, boolean isTitleNeeded) {
         mId = tabId;
         mIsIncognito = isIncognito;
+        mIsNative = isNative;
         init(maxContentTextureWidth, maxContentTextureHeight, showCloseButton, isTitleNeeded);
     }
 
@@ -212,6 +216,7 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      * Initializes the {@link LayoutTab} from data extracted from a {@link Tab}.
      * As this function may be expensive and can be delayed we initialize it as a separately.
      *
+     * @param needsToolbarShadow    Whether the tab will need the toolbar shadow.
      * @param backgroundColor       The color of the page background.
      * @param fallbackThumbnailId   The id of a cached thumbnail to show if the current
      *                              thumbnail is unavailable, or {@link Tab.INVALID_TAB_ID}
@@ -221,8 +226,10 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
      * @param canUseLiveTexture     Whether the tab can use a live texture when being displayed.
      * @return True if the init requires the compositor to update.
      */
-    public boolean initFromHost(int backgroundColor, boolean shouldStall, boolean canUseLiveTexture,
-            int toolbarBackgroundColor, int textBoxBackgroundColor, float textBoxAlpha) {
+    public boolean initFromHost(boolean needsToolbarShadow, int backgroundColor,
+            boolean shouldStall, boolean canUseLiveTexture, int toolbarBackgroundColor,
+            int textBoxBackgroundColor, float textBoxAlpha) {
+        mNeedsToolbarShadow = needsToolbarShadow;
         mBackgroundColor = backgroundColor;
 
         boolean needsUpdate = false;
@@ -497,6 +504,20 @@ public class LayoutTab implements ChromeAnimation.Animatable<LayoutTab.Property>
     }
 
     /**
+     * @return Whether the underlying tab is a native page.
+     */
+    public boolean isNativePage() {
+        return mIsNative;
+    }
+
+    /**
+     * @return Whether the underlying tab needs to draw the toolbar shadow.
+     */
+    public boolean needsToolbarShadow() {
+        return mNeedsToolbarShadow;
+    }
+
+    /**
      * @param y The vertical draw position.
      */
     public void setY(float y) {