Fix bug with phantom input windows.

Add dumpsys integration for the native input dispatcher.
Add some InputDevice API stubs.
Add an appendFormat helper method to String8 for printf style
string formatting mainly for debugging purposes.
Use generic ArrayList<WindowState> everywhere in WindowManagerService
to eliminate unnecessary casts all over.

Change-Id: I9d1e3bd90eb7222d10620200477f11b7bfd25e44

include/utils/String8.h

@@ -171,6 +171,8 @@ public:
             status_t            append(const char* other);
             status_t            append(const char* other, size_t numChars);
 
+            status_t            appendFormat(const char* fmt, ...);
+
             // Note that this function takes O(N) time to calculate the value.
             // No cache value is stored.
             size_t              getUtf32Length() const;

libs/utils/String8.cpp

@@ -372,6 +372,27 @@ status_t String8::append(const char* other, size_t otherLen)
     return real_append(other, otherLen);
 }
 
+status_t String8::appendFormat(const char* fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+
+    int result = NO_ERROR;
+    int n = vsnprintf(NULL, 0, fmt, ap);
+    if (n != 0) {
+        size_t oldLength = length();
+        char* buf = lockBuffer(oldLength + n);
+        if (buf) {
+            vsnprintf(buf + oldLength, n + 1, fmt, ap);
+        } else {
+            result = NO_MEMORY;
+        }
+    }
+
+    va_end(ap);
+    return result;
+}
+
 status_t String8::real_append(const char* other, size_t otherLen)
 {
     const size_t myLen = bytes();
@@ -411,15 +432,16 @@ status_t String8::unlockBuffer(size_t size)
     if (size != this->size()) {
         SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
             ->editResize(size+1);
-        if (buf) {
-            char* str = (char*)buf->data();
-            str[size] = 0;
-            mString = str;
-            return NO_ERROR;
+        if (! buf) {
+            return NO_MEMORY;
         }
+
+        char* str = (char*)buf->data();
+        str[size] = 0;
+        mString = str;
     }
-    
-    return NO_MEMORY;
+
+    return NO_ERROR;
 }
 
 ssize_t String8::find(const char* other, size_t start) const