diff --git a/webrtc/base/checks.cc b/webrtc/base/checks.cc
index dd7183362..67f5003de 100644
--- a/webrtc/base/checks.cc
+++ b/webrtc/base/checks.cc
@@ -15,6 +15,8 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 
+namespace rtc {
+
 void Fatal(const char* file, int line, const char* format, ...) {
   char msg[256];
 
@@ -28,3 +30,5 @@ void Fatal(const char* file, int line, const char* format, ...) {
                 << "\n#\n";
   abort();
 }
+
+}  // namespace rtc
diff --git a/webrtc/base/checks.h b/webrtc/base/checks.h
index 93f7580ed..5a2841ae9 100644
--- a/webrtc/base/checks.h
+++ b/webrtc/base/checks.h
@@ -16,12 +16,15 @@
 
 #include <string.h>
 
+namespace rtc {
+
 // Prints an error message to stderr and aborts execution.
 void Fatal(const char* file, int line, const char* format, ...);
 
+}  // namespace rtc
 
 // The UNREACHABLE macro is very useful during development.
 #define UNREACHABLE()                                   \
-  Fatal(__FILE__, __LINE__, "unreachable code")
+  rtc::Fatal(__FILE__, __LINE__, "unreachable code")
 
 #endif  // WEBRTC_BASE_CHECKS_H_
diff --git a/webrtc/base/flags.cc b/webrtc/base/flags.cc
index bc7a83030..fe7a334a9 100644
--- a/webrtc/base/flags.cc
+++ b/webrtc/base/flags.cc
@@ -20,7 +20,7 @@
 
 #include "webrtc/base/flags.h"
 
-
+namespace rtc {
 // -----------------------------------------------------------------------------
 // Implementation of Flag
 
@@ -296,3 +296,4 @@ WindowsCommandLineArguments::~WindowsCommandLineArguments() {
 }
 #endif  // WEBRTC_WIN 
 
+}  // namespace rtc
diff --git a/webrtc/base/flags.h b/webrtc/base/flags.h
index ac91d8ad6..5cff1cc36 100644
--- a/webrtc/base/flags.h
+++ b/webrtc/base/flags.h
@@ -28,6 +28,8 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/base/common.h"
 
+namespace rtc {
+
 // Internal use only.
 union FlagValue {
   // Note: Because in C++ non-bool values are silently converted into
@@ -155,9 +157,9 @@ class Flag {
   /* define and initialize the flag */                    \
   c_type FLAG_##name = (default);                         \
   /* register the flag */                                 \
-  static Flag Flag_##name(__FILE__, #name, (comment),   \
-                          Flag::type, &FLAG_##name,       \
-                          FlagValue::New_##type(default))
+  static rtc::Flag Flag_##name(__FILE__, #name, (comment),      \
+                               rtc::Flag::type, &FLAG_##name,   \
+                               rtc::FlagValue::New_##type(default))
 
 
 // Internal use only.
@@ -263,5 +265,6 @@ class WindowsCommandLineArguments {
 };
 #endif  // WEBRTC_WIN 
 
+}  // namespace rtc
 
 #endif  // SHARED_COMMANDLINEFLAGS_FLAGS_H__
diff --git a/webrtc/base/ifaddrs-android.cc b/webrtc/base/ifaddrs-android.cc
index 5d022a79a..c8363d567 100644
--- a/webrtc/base/ifaddrs-android.cc
+++ b/webrtc/base/ifaddrs-android.cc
@@ -23,14 +23,18 @@
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
 
+namespace {
+
 struct netlinkrequest {
   nlmsghdr header;
   ifaddrmsg msg;
 };
 
-namespace {
 const int kMaxReadSize = 4096;
-};
+
+}  // namespace
+
+namespace rtc {
 
 int set_ifname(struct ifaddrs* ifaddr, int interface) {
   char buf[IFNAMSIZ] = {0};
@@ -215,3 +219,5 @@ void freeifaddrs(struct ifaddrs* addrs) {
   }
 }
 #endif  // defined(WEBRTC_ANDROID)
+
+}  // namespace rtc
diff --git a/webrtc/base/ifaddrs-android.h b/webrtc/base/ifaddrs-android.h
index c8671e08f..10890af65 100644
--- a/webrtc/base/ifaddrs-android.h
+++ b/webrtc/base/ifaddrs-android.h
@@ -13,6 +13,8 @@
 
 #include <stdio.h>
 #include <sys/socket.h>
+
+
 // Implementation of getifaddrs for Android.
 // Fills out a list of ifaddr structs (see below) which contain information
 // about every network interface available on the host.
@@ -27,7 +29,11 @@ struct ifaddrs {
   // We don't need them (yet?).
 };
 
+namespace rtc {
+
 int getifaddrs(struct ifaddrs** result);
 void freeifaddrs(struct ifaddrs* addrs);
 
+}  // namespace rtc
+
 #endif  // WEBRTC_BASE_IFADDRS_ANDROID_H_
diff --git a/webrtc/base/md5.cc b/webrtc/base/md5.cc
index a4f28d730..54128907a 100644
--- a/webrtc/base/md5.cc
+++ b/webrtc/base/md5.cc
@@ -25,6 +25,8 @@
 
 #include "webrtc/base/byteorder.h"  // for ARCH_CPU_LITTLE_ENDIAN.
 
+namespace rtc {
+
 #ifdef ARCH_CPU_LITTLE_ENDIAN
 #define ByteReverse(buf, len)  // Nothing.
 #else  // ARCH_CPU_BIG_ENDIAN
@@ -216,3 +218,5 @@ void MD5Transform(uint32 buf[4], const uint32 in[16]) {
   buf[2] += c;
   buf[3] += d;
 }
+
+}  // namespace rtc
diff --git a/webrtc/base/md5.h b/webrtc/base/md5.h
index fc563b764..418e214c7 100644
--- a/webrtc/base/md5.h
+++ b/webrtc/base/md5.h
@@ -17,12 +17,15 @@
 
 // Changes(fbarchard): Ported to C++ and Google style guide.
 // Made context first parameter in MD5Final for consistency with Sha1.
+// Changes(hellner): added rtc namespace
 
 #ifndef WEBRTC_BASE_MD5_H_
 #define WEBRTC_BASE_MD5_H_
 
 #include "webrtc/base/basictypes.h"
 
+namespace rtc {
+
 // Canonical name for a MD5 context structure, used in many crypto libs.
 typedef struct MD5Context MD5_CTX;
 
@@ -37,4 +40,6 @@ void MD5Update(MD5Context* context, const uint8* data, size_t len);
 void MD5Final(MD5Context* context, uint8 digest[16]);
 void MD5Transform(uint32 buf[4], const uint32 in[16]);
 
+}  // namespace rtc
+
 #endif  // WEBRTC_BASE_MD5_H_
diff --git a/webrtc/base/openssladapter.cc b/webrtc/base/openssladapter.cc
index d0311100e..c9f6b1aaa 100644
--- a/webrtc/base/openssladapter.cc
+++ b/webrtc/base/openssladapter.cc
@@ -84,9 +84,9 @@ static BIO_METHOD methods_socket = {
   NULL,
 };
 
-BIO_METHOD* BIO_s_socket2() { return(&methods_socket); }
+static BIO_METHOD* BIO_s_socket2() { return(&methods_socket); }
 
-BIO* BIO_new_socket(rtc::AsyncSocket* socket) {
+static BIO* BIO_new_socket(rtc::AsyncSocket* socket) {
   BIO* ret = BIO_new(BIO_s_socket2());
   if (ret == NULL) {
           return NULL;
diff --git a/webrtc/base/sha1.cc b/webrtc/base/sha1.cc
index 8f8bd3d4a..afc5569fd 100644
--- a/webrtc/base/sha1.cc
+++ b/webrtc/base/sha1.cc
@@ -102,6 +102,8 @@
 #include <stdio.h>
 #include <string.h>
 
+namespace rtc {
+
 void SHA1Transform(uint32 state[5], const uint8 buffer[64]);
 
 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
@@ -280,3 +282,5 @@ void SHA1Final(SHA1_CTX* context, uint8 digest[SHA1_DIGEST_SIZE]) {
   SHA1Transform(context->state, context->buffer);
 #endif
 }
+
+}  // namespace rtc
diff --git a/webrtc/base/sha1.h b/webrtc/base/sha1.h
index b19c6592e..4862a0049 100644
--- a/webrtc/base/sha1.h
+++ b/webrtc/base/sha1.h
@@ -5,13 +5,15 @@
  *
 */
 
-// Ported to C++, Google style and uses basictypes.h
+// Ported to C++, Google style, under namespace rtc and uses basictypes.h
 
 #ifndef WEBRTC_BASE_SHA1_H_
 #define WEBRTC_BASE_SHA1_H_
 
 #include "webrtc/base/basictypes.h"
 
+namespace rtc {
+
 struct SHA1_CTX {
   uint32 state[5];
   // TODO: Change bit count to uint64.
@@ -26,3 +28,5 @@ void SHA1Update(SHA1_CTX* context, const uint8* data, size_t len);
 void SHA1Final(SHA1_CTX* context, uint8 digest[SHA1_DIGEST_SIZE]);
 
 #endif  // WEBRTC_BASE_SHA1_H_
+
+}  // namespace rtc
diff --git a/webrtc/base/sslroots.h b/webrtc/base/sslroots.h
index 0f983cd60..31d601c16 100644
--- a/webrtc/base/sslroots.h
+++ b/webrtc/base/sslroots.h
@@ -8,6 +8,7 @@
 /* subject:/C=SE/O=AddTrust AB/OU=AddTrust External TTP Network/CN=AddTrust External CA Root */
 /* issuer :/C=SE/O=AddTrust AB/OU=AddTrust External TTP Network/CN=AddTrust External CA Root */
 
+namespace rtc {
 
 const unsigned char AddTrust_External_Root_certificate[1082]={
 0x30,0x82,0x04,0x36,0x30,0x82,0x03,0x1E,0xA0,0x03,0x02,0x01,0x02,0x02,0x01,0x01,
@@ -4928,3 +4929,4 @@ const size_t kSSLCertCertificateSizeList[] = {
   1076,
 };
 
+}  // namspace rtc
diff --git a/webrtc/base/unittest_main.cc b/webrtc/base/unittest_main.cc
index c7adb7931..7c4630e3c 100644
--- a/webrtc/base/unittest_main.cc
+++ b/webrtc/base/unittest_main.cc
@@ -77,9 +77,9 @@ rtc::Pathname GetTalkDirectory() {
 
 int main(int argc, char** argv) {
   testing::InitGoogleTest(&argc, argv);
-  FlagList::SetFlagsFromCommandLine(&argc, argv, false);
+  rtc::FlagList::SetFlagsFromCommandLine(&argc, argv, false);
   if (FLAG_help) {
-    FlagList::Print(NULL, false);
+    rtc::FlagList::Print(NULL, false);
     return 0;
   }
 
diff --git a/webrtc/base/urlencode.cc b/webrtc/base/urlencode.cc
index 5619e05cb..b152829ae 100644
--- a/webrtc/base/urlencode.cc
+++ b/webrtc/base/urlencode.cc
@@ -36,8 +36,8 @@ static int HexPairValue(const char * code) {
   }
 }
 
-int InternalUrlDecode(const char *source, char *dest,
-                      bool encode_space_as_plus) {
+static int InternalUrlDecode(const char *source, char *dest,
+                             bool encode_space_as_plus) {
   char * start = dest;
 
   while (*source) {
@@ -74,6 +74,16 @@ int InternalUrlDecode(const char *source, char *dest,
   return static_cast<int>(dest - start);
 }
 
+static bool IsValidUrlChar(char ch, bool unsafe_only) {
+  if (unsafe_only) {
+    return !(ch <= ' ' || strchr("\\\"^&`<>[]{}", ch));
+  } else {
+    return isalnum(ch) || strchr("-_.!~*'()", ch);
+  }
+}
+
+namespace rtc {
+
 int UrlDecode(const char *source, char *dest) {
   return InternalUrlDecode(source, dest, true);
 }
@@ -82,14 +92,6 @@ int UrlDecodeWithoutEncodingSpaceAsPlus(const char *source, char *dest) {
   return InternalUrlDecode(source, dest, false);
 }
 
-bool IsValidUrlChar(char ch, bool unsafe_only) {
-  if (unsafe_only) {
-    return !(ch <= ' ' || strchr("\\\"^&`<>[]{}", ch));
-  } else {
-    return isalnum(ch) || strchr("-_.!~*'()", ch);
-  }
-}
-
 int InternalUrlEncode(const char *source, char *dest, unsigned int max,
                       bool encode_space_as_plus, bool unsafe_only) {
   static const char *digits = "0123456789ABCDEF";
@@ -177,3 +179,5 @@ std::string
 UrlEncodeStringForOnlyUnsafeChars(const std::string & decoded) {
   return InternalUrlEncodeString(decoded, false, true);
 }
+
+}  // namespace rtc
diff --git a/webrtc/base/urlencode.h b/webrtc/base/urlencode.h
index 6195f8380..fc10f3880 100644
--- a/webrtc/base/urlencode.h
+++ b/webrtc/base/urlencode.h
@@ -13,6 +13,8 @@
 
 #include <string>
 
+namespace rtc {
+
 // Decode all encoded characters. Also decode + as space.
 int UrlDecode(const char *source, char *dest);
 
@@ -41,3 +43,4 @@ std::string UrlEncodeStringForOnlyUnsafeChars(const std::string & decoded);
 
 #endif
 
+}  // namespace rtc
diff --git a/webrtc/base/urlencode_unittest.cc b/webrtc/base/urlencode_unittest.cc
index 2214fbf2a..52169132e 100644
--- a/webrtc/base/urlencode_unittest.cc
+++ b/webrtc/base/urlencode_unittest.cc
@@ -13,6 +13,8 @@
 #include "webrtc/base/thread.h"
 #include "webrtc/base/urlencode.h"
 
+using rtc::UrlEncode;
+
 TEST(Urlencode, SourceTooLong) {
   char source[] = "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^"
       "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^";
@@ -61,21 +63,21 @@ TEST(Urlencode, Encoding1) {
 TEST(Urlencode, Encoding2) {
   char source[] = "A^ ";
   char dest[8];
-  ASSERT_EQ(7, UrlEncodeWithoutEncodingSpaceAsPlus(source, dest,
-                                                   ARRAY_SIZE(dest)));
+  ASSERT_EQ(7, rtc::UrlEncodeWithoutEncodingSpaceAsPlus(source, dest,
+                                                        ARRAY_SIZE(dest)));
   ASSERT_STREQ("A%5E%20", dest);
 }
 
 TEST(Urldecode, Decoding1) {
   char source[] = "A%5E+";
   char dest[8];
-  ASSERT_EQ(3, UrlDecode(source, dest));
+  ASSERT_EQ(3, rtc::UrlDecode(source, dest));
   ASSERT_STREQ("A^ ", dest);
 }
 
 TEST(Urldecode, Decoding2) {
   char source[] = "A%5E+";
   char dest[8];
-  ASSERT_EQ(3, UrlDecodeWithoutEncodingSpaceAsPlus(source, dest));
+  ASSERT_EQ(3, rtc::UrlDecodeWithoutEncodingSpaceAsPlus(source, dest));
   ASSERT_STREQ("A^+", dest);
 }