Update libchrome to r307740 and fix build errors

Updated libchrome, libchrome_crypto, metrics, feedback to the
latest revisions from Chrome (r307740).

Fixed build breaks due to the changes in upstream code:

- scope_ptr no longer needs explicit PassAs<T>() calls.
- scope_ptr<T> no longer has implicit conversion to T*.
  Must use scope_ptr<T>::get() instead.
- base/file_util.h moved to base/files/file_util.h
- ARRAYSIZE_UNSAFE() removed in favor of arraysize()
- base::AppendToFile() and base::WriteFileDescriptor() now
  return bool instead of the number of bytes written.
- dbus::Bus::AddFilterFunction() now returns void.
- C++11 features are enabled in libchromeos, so all targets
  linking with it now have to support C++11
- OVERRIDE macro is removed in favor of native C++11
  'override' keyword.

BUG=chromium:416628, chromium:411508
TEST=Build the world on x86, x64, ARM. The following builders
     were tried:
       x86-generic-full amd64-generic-full arm-generic-full
       amd64-generic-asan daisy-full nyan-full pre-cq-group
       daisy-release-group sandybridge-release-group
       pineview-release-group
CQ-DEPEND=CL:234450,CL:234980

Change-Id: I374bebe2211d533c4431c82efb8be1cdcb1f405d
Reviewed-on: https://chromium-review.googlesource.com/234440
Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/http_common.cc b/http_common.cc
index 756fa55..7737f4c 100644
--- a/http_common.cc
+++ b/http_common.cc
@@ -42,7 +42,7 @@
 
   bool is_found = false;
   size_t i;
-  for (i = 0; i < ARRAYSIZE_UNSAFE(http_response_table); i++)
+  for (i = 0; i < arraysize(http_response_table); i++)
     if ((is_found = (http_response_table[i].code == code)))
       break;
 
@@ -64,7 +64,7 @@
 
   bool is_found = false;
   size_t i;
-  for (i = 0; i < ARRAYSIZE_UNSAFE(http_content_type_table); i++)
+  for (i = 0; i < arraysize(http_content_type_table); i++)
     if ((is_found = (http_content_type_table[i].type == type)))
       break;