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 3341991646752f023c18c72d74343cc3da814e1b..2fc27cd87ce62458caca7c913b46f3427b3b373f 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
@@ -72,6 +72,8 @@ public class ChromeShellToolbar extends LinearLayout {
     private SuggestionPopup mSuggestionPopup;
 
     private ImageButton mStopReloadButton;
+    private ImageButton mAddButton;
+
     private int mProgress = 0;
     private boolean mLoading = true;
 
@@ -242,6 +244,20 @@ public class ChromeShellToolbar extends LinearLayout {
         });
     }
 
+
+    public void initializeAddButton(boolean tabswitcher) {

[Bernhard Bauer, 2014/11/05 10:01:53]

This should have a Javadoc comment. Also, |tabswitcher| as a boolean parameter
isn't very intuitive: what does a true or false value actually mean?

And finally, there is no need to reinitialize |mAddButton| or set a new
OnClickListener every time we want to hide or show the button.

+        mAddButton = (ImageButton) findViewById(R.id.add_button);
+        mAddButton.setVisibility(tabswitcher ? VISIBLE : GONE);
+        mStopReloadButton.setVisibility(tabswitcher ? GONE : VISIBLE);
+        mAddButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mTabManager.createNewTab();
+            }
+        });
+    }
+
+
     /**
      * @return Current tab that is shown by ChromeShell.
      */