Require Clang to build Linux host binaries

With this CL, Clang 3.5 is required in the host environment to build Mozc for Android, NaCl, and Linux.  What we want to do with this CL is to reduce the number of actively maintained build configurations.

No user visible change is intended with this CL.

Closes Issue 276.

BUG=Issue mozc:276
TEST=compile

git-svn-id: https://mozc.googlecode.com/svn/trunk@506 a6090854-d499-a067-5803-1114d4e51264
diff --git a/src/docker/ubuntu14.04/Dockerfile b/src/docker/ubuntu14.04/Dockerfile
index 9232d83..e84a5d8 100644
--- a/src/docker/ubuntu14.04/Dockerfile
+++ b/src/docker/ubuntu14.04/Dockerfile
@@ -35,7 +35,7 @@
 RUN dpkg --add-architecture i386
 RUN apt-get update
 ## Common packages for linux build environment
-RUN apt install -y g++ python pkg-config subversion git curl bzip2 unzip make
+RUN apt install -y clang-3.5 python pkg-config subversion git curl bzip2 unzip make
 ## Packages for linux desktop version
 RUN apt install -y libibus-1.0-dev libdbus-1-dev libglib2.0-dev subversion libqt4-dev libzinnia-dev tegaki-zinnia-japanese libgtk2.0-dev libxcb-xfixes0-dev
 ## Packages for Android
diff --git a/src/gyp/common.gypi b/src/gyp/common.gypi
index 9e920fa..5e8debd 100644
--- a/src/gyp/common.gypi
+++ b/src/gyp/common.gypi
@@ -158,28 +158,28 @@
       ['target_platform=="Android" and android_compiler=="clang"', {
         'compiler_target': 'clang',
         'compiler_target_version_int': 305,  # Clang 3.5 or higher
-        'compiler_host': 'gcc',
-        'compiler_host_version_int': 406,  # GCC 4.6 or higher
+        'compiler_host': 'clang',
+        'compiler_host_version_int': 305,  # Clang 3.5 or higher
       }],
       ['target_platform=="Android" and android_compiler=="gcc"', {
         'compiler_target': 'gcc',
         'compiler_target_version_int': 409,  # GCC 4.9 or higher
-        'compiler_host': 'gcc',
-        'compiler_host_version_int': 406,  # GCC 4.6 or higher
+        'compiler_host': 'clang',
+        'compiler_host_version_int': 305,  # Clang 3.5 or higher
       }],
       ['target_platform=="NaCl"', {
         'compiler_target': 'clang',
         'compiler_target_version_int': 303,  # Clang 3.3 or higher
-        'compiler_host': 'gcc',
-        'compiler_host_version_int': 406,  # GCC 4.6 or higher
+        'compiler_host': 'clang',
+        'compiler_host_version_int': 305,  # Clang 3.5 or higher
       }],
       ['target_platform=="Linux"', {
         # enable_gtk_renderer represents if mozc_renderer is supported on Linux
         # or not.
-        'compiler_target': 'gcc',
-        'compiler_target_version_int': 406,  # GCC 4.6 or higher
-        'compiler_host': 'gcc',
-        'compiler_host_version_int': 406,  # GCC 4.6 or higher
+        'compiler_target': 'clang',
+        'compiler_target_version_int': 305,  # Clang 3.5 or higher
+        'compiler_host': 'clang',
+        'compiler_host_version_int': 305,  # Clang 3.5 or higher
         'enable_gtk_renderer%': 1,
       }, {  # else
         'enable_gtk_renderer%': 0,
@@ -874,13 +874,23 @@
         ['NM', '<(pnacl_bin_dir)/pnacl-nm'],
         ['READELF', '<(pnacl_bin_dir)/pnacl-readelf'],
         ['AR.host', '<!(which ar)'],
-        ['CC.host', '<!(which gcc)'],
-        ['CXX.host', '<!(which g++)'],
+        ['CC.host', '<!(which clang)'],
+        ['CXX.host', '<!(which clang++)'],
         ['LD.host', '<!(which ld)'],
         ['NM.host', '<!(which nm)'],
         ['READELF.host', '<!(which readelf)'],
       ],
     }],
+    ['target_platform=="Linux"', {
+      'make_global_settings': [
+        ['AR', '<!(which ar)'],
+        ['CC', '<!(which clang)'],
+        ['CXX', '<!(which clang++)'],
+        ['LD', '<!(which ld)'],
+        ['NM', '<!(which nm)'],
+        ['READELF', '<!(which readelf)'],
+      ],
+    }],
     ['target_platform=="Android"', {
       'variables': {
         'ndk_bin_dir%':
@@ -940,8 +950,8 @@
         ['NM', '<(ndk_bin_dir)/<(toolchain_prefix)-nm'],
         ['READELF', '<(ndk_bin_dir)/<(toolchain_prefix)-readelf'],
         ['AR.host', '<!(which ar)'],
-        ['CC.host', '<!(which gcc)'],
-        ['CXX.host', '<!(which g++)'],
+        ['CC.host', '<!(which clang)'],
+        ['CXX.host', '<!(which clang++)'],
         ['LD.host', '<!(which ld)'],
         ['NM.host', '<!(which nm)'],
         ['READELF.host', '<!(which readelf)'],
diff --git a/src/mozc_version_template.txt b/src/mozc_version_template.txt
index 29f5acc..2078b10 100644
--- a/src/mozc_version_template.txt
+++ b/src/mozc_version_template.txt
@@ -1,6 +1,6 @@
 MAJOR=2
 MINOR=16
-BUILD=2032
+BUILD=2033
 REVISION=102
 # NACL_DICTIONARY_VERSION is the target version of the system dictionary to be
 # downloaded by NaCl Mozc.