libweave: Copy chromeos::Error into libweave

To move dependency on libchromeos.

BUG=brillo:1257
TEST=`FEATURES=test emerge-gizmo libweave buffet`
CQ-DEPEND=CL:293873

Change-Id: Icc3df36b34431987802fe752ae4a129438c57a9d
Reviewed-on: https://chromium-review.googlesource.com/293615
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Tested-by: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
diff --git a/libweave/src/privet/cloud_delegate.h b/libweave/src/privet/cloud_delegate.h
index 3b80b2e..5f79a6d 100644
--- a/libweave/src/privet/cloud_delegate.h
+++ b/libweave/src/privet/cloud_delegate.h
@@ -37,7 +37,7 @@
   virtual ~CloudDelegate();
 
   using SuccessCallback = base::Callback<void(const base::DictionaryValue&)>;
-  using ErrorCallback = base::Callback<void(chromeos::Error*)>;
+  using ErrorCallback = base::Callback<void(Error*)>;
 
   class Observer {
    public:
@@ -49,10 +49,10 @@
   };
 
   // Returns the model ID of the device.
-  virtual bool GetModelId(std::string* id, chromeos::ErrorPtr* error) const = 0;
+  virtual bool GetModelId(std::string* id, ErrorPtr* error) const = 0;
 
   // Returns the name of device.
-  virtual bool GetName(std::string* name, chromeos::ErrorPtr* error) const = 0;
+  virtual bool GetName(std::string* name, ErrorPtr* error) const = 0;
 
   // Returns the description of the device.
   virtual std::string GetDescription() const = 0;
@@ -89,7 +89,7 @@
   // Starts GCD setup.
   virtual bool Setup(const std::string& ticket_id,
                      const std::string& user,
-                     chromeos::ErrorPtr* error) = 0;
+                     ErrorPtr* error) = 0;
 
   // Returns cloud id if the registered device or empty string if unregistered.
   virtual std::string GetCloudId() const = 0;