Adding option for adding new tab in tab manager for chrome shell.

chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java

Index: chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
diff --git a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
index 4e0eefd4949e0a2160783c0a733b1296f320e75a..03b46cb33405a53ec91cb041e8f2afce0e343294 100644
--- a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
+++ b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellToolbar.java
@@ -73,6 +73,7 @@ public class ChromeShellToolbar extends LinearLayout {
     private SuggestionPopup mSuggestionPopup;
 
     private ImageButton mStopReloadButton;
+    private ImageButton mAddButton;
     private int mProgress = 0;
     private boolean mLoading = true;
 
@@ -144,6 +145,7 @@ public class ChromeShellToolbar extends LinearLayout {
         initializeTabSwitcherButton();
         initializeMenuButton();
         initializeStopReloadButton();
+        initializeAddButton();
     }
 
     void setMenuHandler(AppMenuHandler menuHandler) {
@@ -247,6 +249,25 @@ public class ChromeShellToolbar extends LinearLayout {
         });
     }
 
+    private void initializeAddButton() {
+        mAddButton = (ImageButton) findViewById(R.id.add_button);
+        mAddButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mTabManager.createNewTab();
+            }
+        });
+    }
+
+    /**
+     * Shows the add button and hides the stop/reload button.
+     * @param tabSwitcherStatus The visibility status of the tab switcher.
+     */
+    public void showAddButton(boolean tabSwitcherStatus) {

[Bernhard Bauer, 2014/11/12 09:23:17]

This parameter could be |visibility|. This class doesn't have to know under
which circumstances it shows the add button, that's what TabManager does.

[divya.bansal, 2014/11/12 09:48:22]

Done.

+        mAddButton.setVisibility(tabSwitcherStatus ? VISIBLE : GONE);
+        mStopReloadButton.setVisibility(tabSwitcherStatus ? GONE : VISIBLE);
+    }
+
     /**
      * @return Current tab that is shown by ChromeShell.
      */