Add level 3 libs and address build warnings

* Fix strict aliasing error in gcc

  [ Merge of http://go/wvgerrit/15856 ]

  This also ensures the alignment of 64-bit memory access in a portable
  way, without using compiler-specific mechanisms like attributes or
  platform-specific mechanisms like memalign.

  (The aliasing error does not show up in clang.)

* Return kNotSupported for non-Widevine init data

  [ Merge of http://go/wvgerrit/15853 ]

  This also improves logging for the init data parser by including a
  verbose message for non-Widevine PSSHs and by using a new IsEOF()
  method to avoid misleading "Unable to read atom size" logs.

* Cast RSA_size() to int

  [ Merge of http://go/wvgerrit/15880 ]

  It has been suggested that this may be unsigned on some versions of
  OpenSSL or BoringSSL.

* Be strict about warnings for CE CDM

  [ Merge of http://go/wvgerrit/15831 ]

  * Enable all warnings and treat warnings as errors in the CE build.
  * Fix all existing warnings (mostly unused variables, consts, and
  functions, and one signed/unsigned comparison).
  * Exclude protobuf warnings rather than maintain a divergent copy.

* Fix release build errors

  [ Merge of http://go/wvgerrit/15855 ]

* Level 3 Build With Android Emulator

  [ Merge of http://go/wvgerrit/15778 ]

  This CL rebuilds the level 3 libraries with the android emulator
  sdk_phone_*.  This seems to avoid problems with the x86 build using
  incorrect compiler flags.

  These libraries work for arm, x86, mips, arm64, and x86_64.  The level
  3 library is disabled for mips64.

  Versions:
  level3/mips/libwvlevel3.a  Level3 Library Sep 30 2015 18:29:50
  level3/arm/libwvlevel3.a  Level3 Library Sep 28 2015 13:18:25
  level3/x86/libwvlevel3.a  Level3 Library Sep 28 2015 13:08:28

Change-Id: I1e50aa78bdc84ecb905f2e55297d4f48b140341c

libwvdrmengine/cdm/core/include/buffer_reader.h

@@ -26,7 +26,8 @@ class BufferReader {
   BufferReader(const uint8_t* buf, size_t size)
       : buf_(buf), size_(buf != NULL ? size : 0), pos_(0) {}
 
-  bool HasBytes(size_t count) { return (pos() + count <= size()); }
+  bool HasBytes(size_t count) const { return pos_ + count <= size_; }
+  bool IsEOF() const { return pos_ >= size_; }
 
   // Read a value from the stream, performing endian correction,
   // and advance the stream pointer.

libwvdrmengine/cdm/core/src/cdm_session.cpp

@@ -48,6 +48,7 @@ CdmSession::CdmSession(CdmClientPropertySet* cdm_client_property_set,
       key_set_id_ = *forced_session_id;
     } else {
       bool ok = GenerateKeySetId(&key_set_id_);
+      (void)ok;  // ok is now used when assertions are turned off.
       assert(ok);
     }
     session_id_ = key_set_id_;

libwvdrmengine/cdm/core/src/initialization_data.cpp

@@ -55,7 +55,7 @@ bool InitializationData::ExtractWidevinePssh(const CdmInitData& init_data,
   // (optional, if version == 1) K * 16 byte key ID.
   // 4 byte size of PSSH data, exclusive. (N)
   // N byte PSSH data.
-  while (1) {
+  while (!reader.IsEOF()) {
     size_t start_pos = reader.pos();
 
     // atom size, used for skipping.
@@ -128,6 +128,7 @@ bool InitializationData::ExtractWidevinePssh(const CdmInitData& init_data,
              "the atom.");
         return false;
       }
+      LOGV("CdmEngine::ExtractWidevinePssh: Skipping non-Widevine PSSH.");
       continue;
     }
 

libwvdrmengine/cdm/core/test/cdm_session_unittest.cpp

@@ -230,7 +230,6 @@ TEST_F(CdmSessionTest, ReInitFail) {
 }
 
 TEST_F(CdmSessionTest, InitFailCryptoError) {
-  CdmSecurityLevel level = kSecurityLevelL1;
   EXPECT_CALL(*crypto_session_, Open(Eq(kLevelDefault)))
       .WillOnce(Return(UNKNOWN_ERROR));
 

libwvdrmengine/cdm/core/test/device_files_unittest.cpp

@@ -1469,7 +1469,6 @@ class DeviceFilesTest : public ::testing::Test {
     CdmAppParameterMap app_parameters;
     size_t start_pos = 0;
     size_t len = str.length();
-    bool more = true;
     while (start_pos < len) {
       size_t name_end_pos = str.find(' ', start_pos);
       if (name_end_pos == std::string::npos) return app_parameters;
@@ -1841,7 +1840,6 @@ TEST_F(DeviceFilesTest, RetrieveLicenses) {
   DeviceFiles device_files;
   EXPECT_TRUE(device_files.Init(kSecurityLevelL1));
   device_files.SetTestFile(&file);
-  DeviceFiles::LicenseState license_state;
   CdmInitData pssh_data;
   CdmKeyMessage key_request;
   CdmKeyResponse key_response;

libwvdrmengine/cdm/core/test/http_socket.cpp

@@ -47,6 +47,7 @@ SSL_CTX* InitSslContext() {
   return ctx;
 }
 
+#if 0
 // unused, may be useful for debugging SSL-related issues.
 void ShowServerCertificate(const SSL* ssl) {
   // gets the server certificate
@@ -64,6 +65,7 @@ void ShowServerCertificate(const SSL* ssl) {
     LOGE("Failed to get server certificate");
   }
 }
+#endif
 
 // Wait for a socket to be ready for reading or writing.
 // Establishing a connection counts as "ready for write".

libwvdrmengine/cdm/core/test/license_unittest.cpp

@@ -16,7 +16,6 @@ namespace wvcdm {
 
 namespace {
 
-const uint32_t kAesBlockSize = 16;
 const std::string kAesKey = a2bs_hex("000102030405060708090a0b0c0d0e0f");
 const std::string kAesIv = a2bs_hex("000102030405060708090a0b0c0d0e0f");
 const std::string kCencInitDataHdr = a2bs_hex(