[Samsung Galaxy Nexus] Nemed:
The only error i got during lock/unlock screen is this:

E/Tuna PowerHAL( 608): Error opening /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate: No such file or directory
E/Tuna PowerHAL( 608): Error opening /sys/devices/system/cpu/cpufreq/intellidemand/sampling_rate: No such file or directory
E/auditd (20988): Failed on audit_set_pid with error: Protocol not supported
W/ActivityManager( 608): getAssistContextExtras failed: no resumed activity
E/Tuna PowerHAL( 608): Error opening /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate: No such file or directory
E/Tuna PowerHAL( 608): Error opening /sys/devices/system/cpu/cpufreq/intellidemand/sampling_rate: No such file or directory
W/InputMethodManagerService( 608): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@64de76a8 attribute=android.view.inputmethod.EditorInfo@64fdca08, token = android.os.BinderProxy@65091660

And this is what i got during a freeze while browsing:

W/browser (15180): Console: The page at https://news.google.it/nwshp?hl=it&tab=wn&ei=kbNOUtP-N6OS4ATc_oGoBQ&ved=0CAsQqS4oBQ displayed insecure content from android-webview:default_video_poster/963253719504346510.
W/browser (15180): https://news.google.it/nwshp?hl=it&tab=wn&ei=kbNOUtP-N6OS4ATc_oGoBQ&ved=0CAsQqS4oBQ:0
W/art (15180): Thread[35,tid=15209,Native,Thread*=0x42f7abc8,peer=0x64c7c840,"Thread-918"] attached without supplying a name
W/art (15180): Thread[36,tid=16330,Native,Thread*=0x40562298,peer=0x64c7ca38,"Thread-919"] attached without supplying a name
E/auditd (21735): Failed on audit_set_pid with error: Protocol not supported
E/auditd (21740): Failed on audit_set_pid with error: Protocol not supported
E/auditd (21744): Failed on audit_set_pid with error: Protocol not supported
F/libc (15180): Fatal signal 6 (SIGABRT) at 0x00000260 (code=0), thread 15180 (android.browser)
E/ActivityManager( 608): ANR in com.android.browser (com.android.browser/.BrowserActivity)
E/ActivityManager( 608): PID: 15180
E/ActivityManager( 608): Reason: Input dispatching timed out (Waiting because the touched window has not finished processing the input events that were previously delivered to it.)
E/ActivityManager( 608): Load: 1.56 / 1.07 / 1.6
E/ActivityManager( 608): CPU usage from 6148ms to 0ms ago:
E/ActivityManager( 608): 97% 146/surfaceflinger: 0% user + 97% kernel
E/ActivityManager( 608): 2.4% 15180/com.android.browser: 2.1% user + 0.3% kernel / faults: 211 minor
E/ActivityManager( 608): 1.4% 608/system_server: 1.1% user + 0.3% kernel / faults: 357 minor 9 major
E/ActivityManager( 608): 0.6% 106/uksmd: 0% user + 0.6% kernel
E/ActivityManager( 608): 0.6% 125/irq/206-mms_ts: 0% user + 0.6% kernel
E/ActivityManager( 608): 0.1% 1//init: 0% user + 0.1% kernel / faults: 22 minor
E/ActivityManager( 608): 0.1% 98/mmcqd/0: 0% user + 0.1% kernel
E/ActivityManager( 608): 0.1% 109/dhd_dpc: 0% user + 0.1% kernel
E/ActivityManager( 608): 0.1% 13837/com.facebook.katana: 0.1% user + 0% kernel / faults: 1 minor
E/ActivityManager( 608): 0.1% 19565/kworker/u:1: 0% user + 0.1% kernel
E/ActivityManager( 608): 0.1% 21428/kworker/u:2: 0% user + 0.1% kernel
E/ActivityManager( 608): 99% TOTAL: 2.5% user + 96% kernel + 0.1% iowait + 0.1% softirq
E/ActivityManager( 608): CPU usage from 3632ms to 4158ms later:
E/ActivityManager( 608): 58% 15180/com.android.browser: 52% user + 5.6% kernel / faults: 274 minor
E/ActivityManager( 608): 35% 15180/android.browser: 33% user + 1.8% kernel
E/ActivityManager( 608): 13% 15217/Thread-847: 11% user + 1.8% kernel
E/ActivityManager( 608): 3.7% 21696/Thread-912: 3.7% user + 0% kernel
E/ActivityManager( 608): 1.8% 15208/Thread-842: 1.8% user + 0% kernel
E/ActivityManager( 608): 7.5% 146/surfaceflinger: 3.7% user + 3.7% kernel
E/ActivityManager( 608): 3.7% 146/surfaceflinger: 3.7% user + 0% kernel
E/ActivityManager( 608): 1.8% 253/surfaceflinger: 0% user + 1.8% kernel
E/ActivityManager( 608): 7.5% 608/system_server: 0% user + 7.5% kernel / faults: 7 minor
E/ActivityManager( 608): 5.6% 626/ActivityManager: 0% user + 5.6% kernel
E/ActivityManager( 608): 1.8% 663/InputDispatcher: 0% user + 1.8% kernel
E/ActivityManager( 608): 1.1% 106/uksmd: 0% user + 1.1% kernel
E/ActivityManager( 608): 1.8% 11868/kworker/u:3: 0% user + 1.8% kernel
E/ActivityManager( 608): 1.4% 19565/kworker/u:1: 0% user + 1.4% kernel
E/ActivityManager( 608): 1.4% 21428/kworker/u:2: 0% user + 1.4% kernel
E/ActivityManager( 608): 62% TOTAL: 42% user + 20% kernel
E/ActivityManager( 608): Error reading /data/anr/traces.txt
E/ActivityManager( 608): java.io.FileNotFoundException: /data/anr/traces.txt: open failed: ENOENT (No such file or directory)
E/ActivityManager( 608):	at libcore.io.IoBridge.open(IoBridge.java:409)
E/ActivityManager( 608):	at java.io.FileInputStream.<init>(FileInputStream.java:78)
E/ActivityManager( 608):	at android.os.FileUtils.readTextFile(FileUtils.java:236)
E/ActivityManager( 608):	at com.android.server.am.ActivityManagerService$18.run(ActivityManagerService.java:10101)
E/ActivityManager( 608): Caused by: libcore.io.ErrnoException: open failed: ENOENT (No such file or directory)
E/ActivityManager( 608):	at libcore.io.Posix.open(Native Method)
E/ActivityManager( 608):	at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
E/ActivityManager( 608):	at libcore.io.IoBridge.open(IoBridge.java:393)
E/ActivityManager( 608):	... 3 more
W/ActivityManager( 608): Force removing ActivityRecord{64960108 u0 com.android.browser/.BrowserActivity t79}: app died, no saved state

Hope this may help you...