Use on-device font to render keytop icons

We made several changes around keytop icon rendering logic for 1) better
and 2) uniform look-and-feel across various devices.

 - First version showed its keytop icon as bitmap (including 9-patch).
 - Next version embed commercial font's vector image (like <path> in
   SVG) to better scaling.
 - Since 2014 (Android-L (== Material Design) year) subset font has used
   as Noto font (redistribution free) was getting ready. However there
   is no such .otf file which supports both alphabet and hiragana, we
   have to maintain our own font file having both.

Now that Noto font has been getting common across devices.  The number
of devices that have uncommon Japanese font is decreasing.  In order to
reduce maintenance cost, with this CL we start using on-device font to
render keytop icons.

BUG=
TEST=
REF_BUG=32129862
REF_CL=136007063,136444127
REF_TIME=2016-10-18T16:53:08+09:00
REF_TIME_RAW=1476777188 +0900

.gitmodules

@@ -1,9 +1,6 @@
 [submodule "src/third_party/breakpad"]
 	path = src/third_party/breakpad
 	url = https://chromium.googlesource.com/breakpad/breakpad
-[submodule "src/third_party/fontTools"]
-	path = src/third_party/fontTools
-	url = https://github.com/googlei18n/fonttools.git
 [submodule "src/third_party/gtest"]
 	path = src/third_party/gtest
 	url = https://github.com/google/googletest.git

src/android/android.gyp

@@ -155,7 +155,6 @@
         'mozc',
         'guava_library',
         'userfeedback/userfeedback.gyp:userfeedback_project',
-        'subset_font',
         'resources/resources.gyp:resources_project',
         'support_libraries',
       ],
@@ -474,38 +473,6 @@
         },
       ],
     },
-    {
-      'target_name': 'subset_font',
-      'type': 'none',
-      'dependencies': [
-        'resources/resources.gyp:copy_asis_svg',
-        'resources/resources.gyp:transform_template_svg',
-      ],
-      'variables': {
-        'input_font': '<(font_dir)/Noto-Roboto2-Regular.otf',
-        'fonttools_path': '<(third_party_dir)/fontTools/Lib/fontTools',
-      },
-      'actions': [
-        {
-          'action_name': 'make_subset_font',
-          'inputs': [
-            '<(input_font)',
-            'gen_subset_font.py',
-          ],
-          'outputs': [
-            '<(sdk_asset_dir)/subset_font.otf',
-          ],
-          'action': [
-            'python',
-            'gen_subset_font.py',
-            '--svg_paths=<(shared_intermediate_mozc_dir)/data/images/android/svg/transformed.zip,<(shared_intermediate_mozc_dir)/data/images/android/svg/asis.zip',
-            '--input_font', '<(input_font)',
-            '--output_font', '<@(_outputs)',
-            '--fonttools_path', '<(fonttools_path)',
-          ],
-        },
-      ],
-    },
     {
       # The final artifact of the native layer, libmozc.so.
       # Gyp generates executable artifact to <(PRODUCT_DIR),