Add RTC_ prefix to (D)CHECKs and related macros.

We must remove dependency on Chromium, i.e. we can't use Chromium's base/logging.h. That means we need to define these macros in WebRTC also when doing Chromium builds. And this causes redefinition.

Alternative solutions:
* Check if we already have defined e.g. CHECK, and don't define them in that case. This makes us depend on include order in Chromium, which is not acceptable.
* Don't allow using the macros in WebRTC headers. Error prone since if someone adds it there by mistake it may compile fine, but later break if a header in added or order is changed in Chromium. That will be confusing and hard to enforce.
* Ensure that headers that are included by an embedder don't include our macros. This would require some heavy refactoring to be maintainable and enforcable.
* Changes in Chromium for this is obviously not an option.

BUG=chromium:468375
NOTRY=true

Review URL: https://codereview.webrtc.org/1335923002

Cr-Commit-Position: refs/heads/master@{#9964}

webrtc/modules/utility/interface/helpers_android.h

@@ -16,8 +16,8 @@
 
 // Abort the process if |jni| has a Java exception pending.
 // TODO(henrika): merge with CHECK_JNI_EXCEPTION() in jni_helpers.h.
-#define CHECK_EXCEPTION(jni)    \
-  CHECK(!jni->ExceptionCheck()) \
+#define CHECK_EXCEPTION(jni)        \
+  RTC_CHECK(!jni->ExceptionCheck()) \
       << (jni->ExceptionDescribe(), jni->ExceptionClear(), "")
 
 namespace webrtc {
@@ -31,8 +31,8 @@ JNIEnv* GetEnv(JavaVM* jvm);
 jlong PointerTojlong(void* ptr);
 
 // JNIEnv-helper methods that wraps the API which uses the JNI interface
-// pointer (JNIEnv*). It allows us to CHECK success and that no Java exception
-// is thrown while calling the method.
+// pointer (JNIEnv*). It allows us to RTC_CHECK success and that no Java
+// exception is thrown while calling the method.
 jmethodID GetMethodID(
     JNIEnv* jni, jclass c, const char* name, const char* signature);