Makes the component installers return a Result instead of a bool.

This allows conveying more error information from the component
installers to other layers of the component updater.

Before this change, the component install execution path could
only return one error. We are trying to understand the reasons
why the component installers fail.

BUG=615669

Committed: https://crrev.com/73769a84d74113a4a10e4152e63d219eb72f2630
Review-Url: https://codereview.chromium.org/2479633003
Cr-Original-Commit-Position: refs/heads/master@{#429995}
Cr-Commit-Position: refs/heads/master@{#430333}
diff --git a/components/component_updater/component_updater_service_unittest.cc b/components/component_updater/component_updater_service_unittest.cc
index 091cf8da..c4e6199e 100644
--- a/components/component_updater/component_updater_service_unittest.cc
+++ b/components/component_updater/component_updater_service_unittest.cc
@@ -30,6 +30,7 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 using Configurator = update_client::Configurator;
+using Result = update_client::CrxInstaller::Result;
 using TestConfigurator = update_client::TestConfigurator;
 using UpdateClient = update_client::UpdateClient;
 
@@ -47,8 +48,8 @@
 
   MOCK_METHOD1(OnUpdateError, void(int error));
   MOCK_METHOD2(Install,
-               bool(const base::DictionaryValue& manifest,
-                    const base::FilePath& unpack_path));
+               Result(const base::DictionaryValue& manifest,
+                      const base::FilePath& unpack_path));
   MOCK_METHOD2(GetInstalledFile,
                bool(const std::string& file, base::FilePath* installed_file));
   MOCK_METHOD0(Uninstall, bool());