NTP: fix bad layout when navigating back from a page with a theme-color.

chrome/android/java/res/layout/new_tab_page_layout.xml

Index: chrome/android/java/res/layout/new_tab_page_layout.xml
diff --git a/chrome/android/java/res/layout/new_tab_page_layout.xml b/chrome/android/java/res/layout/new_tab_page_layout.xml
index b8dfd5ae24bc4a317dde70536d03e249227220bc..89d1f2145548759983c8acb4a7372c856d6003de 100644
--- a/chrome/android/java/res/layout/new_tab_page_layout.xml
+++ b/chrome/android/java/res/layout/new_tab_page_layout.xml
@@ -14,9 +14,9 @@
     android:paddingTop="@dimen/toolbar_height_no_shadow"
     android:visibility="gone" >
 
-    <!-- Spacer. Note: this must have layout_weight="1" and the other spacers must have
-         layout_weight="0". The NewTabPageLayout will redistribute the extra space between
-         them. -->
+    <!-- Top spacer. Note: the top spacer must have layout_weight="1" and the middle and bottom
+         spacers must have layout_weight="0". The NewTabPageLayout will redistribute the extra space
+         between them. -->
     <View
         android:id="@+id/ntp_top_spacer"
         android:layout_width="0dp"
@@ -70,7 +70,7 @@
             android:src="@drawable/btn_mic" />
     </LinearLayout>
 
-    <!-- Spacer -->
+    <!-- Middle spacer -->
     <View
         android:id="@+id/ntp_middle_spacer"
         android:layout_width="0dp"
@@ -99,7 +99,7 @@
         android:inflatedId="@+id/most_visited_placeholder"
         android:layout="@layout/most_visited_placeholder" />
 
-    <!-- Spacer -->
+    <!-- Bottom spacer -->
     <View
         android:id="@+id/ntp_bottom_spacer"
         android:layout_width="0dp"
@@ -107,6 +107,7 @@
         android:layout_weight="0"
         android:visibility="invisible" />
 
+    <!--  Logo spacer -->
     <View
         android:id="@+id/no_search_logo_spacer"
         android:layout_width="match_parent"
@@ -114,6 +115,7 @@
         android:layout_weight="1"
         android:visibility="gone" />
 
+    <!--  Scroll spacer -->
     <View
         android:id="@+id/ntp_scroll_spacer"
         android:layout_width="match_parent"