Added support for Resize Task

Test: tested flashall on raven
Bug: 194686221
Change-Id: I60586756b2d5f99848a664def8204c0bd47d7e67
diff --git a/fastboot/task.h b/fastboot/task.h
index 630278a..7aa19a3 100644
--- a/fastboot/task.h
+++ b/fastboot/task.h
@@ -79,3 +79,16 @@
   private:
     FlashingPlan* fp_;
 };
+
+class ResizeTask : public Task {
+  public:
+    ResizeTask(FlashingPlan* fp, const std::string& pname, const std::string& size,
+               const std::string& slot);
+    void Run() override;
+
+  private:
+    FlashingPlan* fp_;
+    const std::string pname_;
+    const std::string size_;
+    const std::string slot_;
+};