Fix silly bugs around overscan flag detection.

- we want to check a data block of a specific tag and enough length,
  which doesn't mean && here.
- data_block skipping length is different between two continue

BUG=226318
TEST=ui_unittests passed


Review URL: https://chromiumcodereview.appspot.com/13648004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192497 0039d316-1c4b-4281-b951-d872f2087c98

ui/base/x/x11_util.cc

@@ -1443,14 +1443,14 @@ bool ParseOutputOverscanFlag(const unsigned char* prop,
           nitems)
         break;
 
-      if (tag != kExtendedTag && payload_length < 2) {
+      if (tag != kExtendedTag || payload_length < 2) {
         data_block += payload_length + 1;
         continue;
       }
 
       unsigned char extended_tag_code = data_block[1];
       if (extended_tag_code != kExtendedVideoCapabilityTag) {
-        data_block += payload_length;
+        data_block += payload_length + 1;
         continue;
       }
 

ui/base/x/x11_util_unittest.cc

@@ -54,6 +54,25 @@ const unsigned char kOverscanDisplay[] =
     "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
     "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xc6";
 
+// The EDID info misdetecting overscan once. see crbug.com/226318
+const unsigned char kMisdetecedDisplay[] =
+    "\x00\xff\xff\xff\xff\xff\xff\x00\x10\xac\x64\x40\x4c\x30\x30\x32"
+    "\x0c\x15\x01\x03\x80\x40\x28\x78\xea\x8d\x85\xad\x4f\x35\xb1\x25"
+    "\x0e\x50\x54\xa5\x4b\x00\x71\x4f\x81\x00\x81\x80\xd1\x00\xa9\x40"
+    "\x01\x01\x01\x01\x01\x01\x28\x3c\x80\xa0\x70\xb0\x23\x40\x30\x20"
+    "\x36\x00\x81\x91\x21\x00\x00\x1a\x00\x00\x00\xff\x00\x50\x48\x35"
+    "\x4e\x59\x31\x33\x4e\x32\x30\x30\x4c\x0a\x00\x00\x00\xfc\x00\x44"
+    "\x45\x4c\x4c\x20\x55\x33\x30\x31\x31\x0a\x20\x20\x00\x00\x00\xfd"
+    "\x00\x31\x56\x1d\x5e\x12\x00\x0a\x20\x20\x20\x20\x20\x20\x01\x38"
+    "\x02\x03\x29\xf1\x50\x90\x05\x04\x03\x02\x07\x16\x01\x06\x11\x12"
+    "\x15\x13\x14\x1f\x20\x23\x0d\x7f\x07\x83\x0f\x00\x00\x67\x03\x0c"
+    "\x00\x10\x00\x38\x2d\xe3\x05\x03\x01\x02\x3a\x80\x18\x71\x38\x2d"
+    "\x40\x58\x2c\x45\x00\x81\x91\x21\x00\x00\x1e\x01\x1d\x80\x18\x71"
+    "\x1c\x16\x20\x58\x2c\x25\x00\x81\x91\x21\x00\x00\x9e\x01\x1d\x00"
+    "\x72\x51\xd0\x1e\x20\x6e\x28\x55\x00\x81\x91\x21\x00\x00\x1e\x8c"
+    "\x0a\xd0\x8a\x20\xe0\x2d\x10\x10\x3e\x96\x00\x81\x91\x21\x00\x00"
+    "\x18\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x94";
+
 }
 
 TEST(X11UtilTest, ParseEDID) {
@@ -141,6 +160,10 @@ TEST(X11UtilTest, ParseOverscanFlag) {
       kOverscanDisplay, charsize(kOverscanDisplay), &flag));
   EXPECT_TRUE(flag);
 
+  flag = false;
+  EXPECT_FALSE(ParseOutputOverscanFlag(
+      kMisdetecedDisplay, charsize(kMisdetecedDisplay), &flag));
+
   flag = false;
   // Copy |kOverscanDisplay| and set flags to false in it. The overscan flags
   // are embedded at byte 150 in this specific example. Fix here too when the