Don't use clang by default when cross building for ARM/linux.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 58a1bf24cf67d6a7586e70039e11371f94576819..dfa527c1ca6616fa312379205f6408b632757d18 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1780,7 +1780,7 @@
         # the class names, so the JNI generator needs to know this.
         'jni_generator_jarjar_file': '../android_webview/build/jarjar-rules.txt',
       }],
-      ['OS=="linux" and target_arch!="mipsel"', {
+      ['OS=="linux" and target_arch!="mipsel" and target_arch!="arm"', {
         # TODO(thakis): This is here to measure perf for a while.
         'clang%': 1,
       }],  # OS=="mac"
@@ -4268,6 +4268,18 @@
               '-Wl,--disable-new-dtags',
             ],
           }],
+          # TODO(sbc): remove this once we switch to clang or gcc >= 4.8 for
+          # for ARM/linux cross compiling. http://crbug.com/395832
+          ['gcc_version>=46 and gcc_version<48 and clang==0', {
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags_cc': [
+                  '-std=gnu++0x',

[Nico, 2014/07/22 22:26:26]

Oh, I missed this. I really don't want to have a bot that uses 4.6 and
std=gnu++0x. There are many known compiler bugs with c++11 and 4.6, which is why
we're not supporting this configuration in the first place.

The way forward for this bot is either clang or a qemu with gcc 4.8 and whatnot
as suggested by jam.

[Sam Clegg, 2014/07/23 00:35:50]

OK.  I'll keep pushing forward with clang.

Should we error out if gccversion>0 && gccversion<48 than?

[Nico, 2014/07/23 00:40:10]

Yes. That's blocked on someone (likely me :-) ) to figure out the "a better fix"
thing described at https://codereview.chromium.org/379693003/ , as under certain
conditions gcc_version is not 0 even with clang at the moment.

+                  '-fpermissive',
+                ],
+              }],
+            ],
+          }],
           ['gcc_version>=48 and clang==0', {
             'target_conditions': [
               ['_toolset=="target"', {