web_setting: Fix coding style violations.

./web_setting/web_setting.h:20:  Lines should be <= 80 characters long  [whitespace/line_length] [2]

BUG=XWALK-2649
common: Fix coding style violations.

./common/virtual_fs.cc:57:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:58:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:61:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:62:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:63:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:64:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:65:  Lines should be <= 80 characters long  [whitespace/line_length] [2]
./common/virtual_fs.cc:66:  Lines should be <= 80 characters long  [whitespace/line_length] [2]

BUG=XWALK-2649
system_info: Fix coding style violations.

./system_info/system_info_sim_ivi.cc:129:  If an else has a brace on one side, it should have it on both  [readability/braces] [5]
./system_info/system_info_locale.h:35:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_cellular_network.h:34:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_network.h:54:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_wifi_network.h:44:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_cpu.h:37:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_device_orientation.h:41:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_peripheral.h:34:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_battery.h:38:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_build.h:44:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]
./system_info/system_info_display.h:48:  Zero-parameter constructors should not be marked explicit.  [runtime/explicit] [5]

BUG=XWALK-2649
Merge pull request #379 from rakuco/fix-style-issues

Fix coding style issues in the code base.