android: add ThumbnailCache

chrome/browser/android/tab_android.h

Index: chrome/browser/android/tab_android.h
diff --git a/chrome/browser/android/tab_android.h b/chrome/browser/android/tab_android.h
index 9435eca2c2079bbf7aebb0e40190fb98ccaa4d3c..bef465d8e02bb3ac3fc91052c6e17ffc82f112f5 100644
--- a/chrome/browser/android/tab_android.h
+++ b/chrome/browser/android/tab_android.h
@@ -11,6 +11,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
+#include "chrome/browser/android/tab_thumbnail_provider.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "chrome/browser/sync/glue/synced_tab_delegate_android.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h"
@@ -42,7 +43,8 @@ class PrerenderManager;
 }
 
 class TabAndroid : public CoreTabHelperDelegate,
-                   public content::NotificationObserver {
+                   public content::NotificationObserver,
+                   public TabThumbnailProvider {
  public:
   enum TabLoadStatus {
 #define DEFINE_TAB_LOAD_STATUS(name, value)  name = value,
@@ -71,21 +73,17 @@ class TabAndroid : public CoreTabHelperDelegate,
 
   // Return specific id information regarding this TabAndroid.
   const SessionID& session_id() const { return session_tab_id_; }
-  int GetAndroidId() const;
+
   int GetSyncId() const;
 
   // Return the tab title.
   base::string16 GetTitle() const;
 
-  // Return the tab url.
-  GURL GetURL() const;
-
   // Load the tab if it was unloaded from memory.
   bool LoadIfNeeded();
 
   // Helper methods to make it easier to access objects from the associated
   // WebContents.  Can return NULL.
-  content::ContentViewCore* GetContentViewCore() const;
   Profile* GetProfile() const;
   browser_sync::SyncedTabDelegate* GetSyncedTabDelegate() const;
 
@@ -104,6 +102,13 @@ class TabAndroid : public CoreTabHelperDelegate,
 
   bool HasPrerenderedUrl(GURL gurl);
 
+  // TabThumbnailProvider -----------------------------------------------------
+  // The unique Id associated with the Android-side of this tab.
+  virtual int GetAndroidId() const OVERRIDE;
+  // Return the tab url.
+  virtual GURL GetURL() const OVERRIDE;
+  virtual content::ContentViewCore* GetContentViewCore() const OVERRIDE;
+
   // CoreTabHelperDelegate ----------------------------------------------------
 
   virtual void SwapTabContents(content::WebContents* old_contents,