Let content_unittests almost build with the components build on android

content/renderer/android/email_detector.h

Index: content/renderer/android/email_detector.h
diff --git a/content/renderer/android/email_detector.h b/content/renderer/android/email_detector.h
index 3bd4d41e642896f7a5e04fd0d9be9bedb7451b09..dbd6de3fb7113c90057abedd28fdea9e839e66a9 100644
--- a/content/renderer/android/email_detector.h
+++ b/content/renderer/android/email_detector.h
@@ -6,6 +6,7 @@
 #define CONTENT_RENDERER_ANDROID_EMAIL_DETECTOR_H_
 
 #include "base/compiler_specific.h"
+#include "content/common/content_export.h"
 #include "content/renderer/android/content_detector.h"
 
 namespace content {
@@ -14,7 +15,7 @@ class EmailDetectorTest;
 
 // Finds email addresses (in most common formats, but not including special
 // characters) in the given text string.
-class EmailDetector : public ContentDetector {
+class CONTENT_EXPORT EmailDetector : public ContentDetector {
  public:
   EmailDetector();