Added a UI for the Interests Prototype.

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
index 16c39b3ef7424f483a39f1d51ccd100b08dd6eb7..43de832b80027cfae0e6b6026b9073e2788bc5ec 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
@@ -119,6 +119,9 @@ public class NewTabPageView extends FrameLayout
         /** @return Whether voice search is enabled and the microphone should be shown. */
         boolean isVoiceSearchEnabled();
 
+        /** @return Whether the NTP Interests tab is enabled and its button should be shown. */
+        boolean isInterestsEnabled();
+
         /** @return Whether the document mode opt out promo should be shown. */
         boolean shouldShowOptOutPromo();
 
@@ -137,6 +140,9 @@ public class NewTabPageView extends FrameLayout
         /** Opens a given URL in the current tab. */
         void open(String url);
 
+        /** Opens the interests dialog. */
+        void navigateToInterests();
+
         /**
          * Animates the search box up into the omnibox and bring up the keyboard.
          * @param beginVoiceSearch Whether to begin a voice search.
@@ -313,6 +319,12 @@ public class NewTabPageView extends FrameLayout
                 mManager.navigateToBookmarks();
             }
         });
+        toolbar.getInterestsButton().setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mManager.navigateToInterests();
+            }
+        });
 
         initializeSearchBoxScrollHandling();
         addOnLayoutChangeListener(this);
@@ -347,6 +359,11 @@ public class NewTabPageView extends FrameLayout
                 }
             });
         }
+
+        // Set up interests
+        if (manager.isInterestsEnabled()) {
+            toolbar.getInterestsButton().setVisibility(View.VISIBLE);
+        }
     }
 
     private int getTabsMovedIllustration() {