Update and unify nine-patch files for content suggestion and omnibox cards

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java
index 05a102fe16ae14529b25f788ebd1a2575caf5364..4eff2c8841524821a5facb40ce6f55c406fb36ba 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardViewHolder.java
@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser.ntp.cards;
 
+import android.graphics.Rect;
 import android.support.annotation.CallSuper;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.Nullable;
@@ -18,6 +19,7 @@ import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.view.animation.Interpolator;
 
+import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ntp.ContextMenuManager;
 import org.chromium.chrome.browser.ntp.UiConfig;
@@ -48,11 +50,16 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
     private final int mMaxPeekPadding;
 
     /**
-     * Due to the card background being a 9 patch file - the card border shadow will be part of
-     * the card width and height. This value will be used to adjust values to account for the
-     * borders.
+     * The card shadow is part of the drawable nine-patch and not drawn via setElevation(),
+     * so it is included in the height and width of the drawable. This member contains the
+     * dimensions of the shadow (from the drawable's padding), so it can be used to offset the
+     * position in calculations.
      */
-    private final int mCards9PatchAdjustment;
+    private final Rect mCardShadow = new Rect();
+
+    private final int mCardGap;
+
+    private final int mDefaultLateralMargin;
 
     protected final NewTabPageRecyclerView mRecyclerView;
 
@@ -78,8 +85,10 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
             UiConfig uiConfig, final ContextMenuManager contextMenuManager) {
         super(inflateView(layoutId, recyclerView));
 
-        mCards9PatchAdjustment = recyclerView.getResources().getDimensionPixelSize(
-                R.dimen.snippets_card_9_patch_adjustment);
+        ApiCompatibilityUtils.getDrawable(recyclerView.getResources(), R.drawable.card_single)
+                .getPadding(mCardShadow);
+
+        mCardGap = recyclerView.getResources().getDimensionPixelSize(R.dimen.snippets_card_gap);
 
         mMaxPeekPadding = recyclerView.getResources().getDimensionPixelSize(
                 R.dimen.snippets_padding);
@@ -115,7 +124,11 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
 
         // Configure the resizer to use negative margins on regular display to balance out the
         // lateral shadow of the card 9-patch and avoid a rounded corner effect.
-        mMarginResizer.setMargins(-mCards9PatchAdjustment);
+        int cardCornerRadius = recyclerView.getResources().getDimensionPixelSize(
+                R.dimen.snippets_card_corner_radius);
+        assert mCardShadow.left == mCardShadow.right;
+        mDefaultLateralMargin = -(mCardShadow.left + cardCornerRadius);
+        mMarginResizer.setMargins(mDefaultLateralMargin);
     }
 
     /**
@@ -176,7 +189,11 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
             hasCardBelow = isCard(belowViewType) && belowViewType != ItemViewType.PROMO;
         }
 
-        getParams().bottomMargin = hasCardBelow ? -mCards9PatchAdjustment : 0;
+        // By default the apparent distance between two cards is the sum of the bottom and top
+        // height of their shadows. We want |mCardGap| instead, so we set the bottom margin to
+        // the difference.
+        getParams().bottomMargin =
+                hasCardBelow ? (mCardGap - (mCardShadow.top + mCardShadow.bottom)) : 0;
 
         @DrawableRes
         int selectedBackground = selectBackground(hasCardAbove, hasCardBelow);
@@ -247,9 +264,8 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
         }
         itemView.setPadding(lateralPadding, mMaxPeekPadding, lateralPadding, mMaxPeekPadding);
 
-        // Adjust the margins by |mCards9PatchAdjustment| so the card width
-        // is the actual width not including the elevation shadow, so we can have full bleed.
-        mMarginResizer.setMargins(mMaxPeekPadding - (peekPadding + mCards9PatchAdjustment));
+        // Adjust the margins. The shadow width is offset via the default lateral margin.
+        mMarginResizer.setMargins(mDefaultLateralMargin + mMaxPeekPadding - peekPadding);
 
         // Set the opacity of the card content to be 0 when peeking and 1 when full width.
         int itemViewChildCount = ((ViewGroup) itemView).getChildCount();
@@ -285,10 +301,10 @@ public abstract class CardViewHolder extends NewTabPageViewHolder {
 
     @DrawableRes
     protected int selectBackground(boolean hasCardAbove, boolean hasCardBelow) {
-        if (hasCardAbove && hasCardBelow) return R.drawable.ntp_card_middle;
-        if (!hasCardAbove && hasCardBelow) return R.drawable.ntp_card_top;
-        if (hasCardAbove && !hasCardBelow) return R.drawable.ntp_card_bottom;
-        return R.drawable.ntp_card_single;
+        if (hasCardAbove && hasCardBelow) return R.drawable.card_middle;
+        if (!hasCardAbove && hasCardBelow) return R.drawable.card_top;
+        if (hasCardAbove && !hasCardBelow) return R.drawable.card_bottom;
+        return R.drawable.card_single;
     }
 
     protected NewTabPageRecyclerView getRecyclerView() {