Add multiline braille support.

chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc

Index: chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc
diff --git a/chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc b/chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc
index 78e84507d677a81fe3bf0b41b9dcd1ae20590738..e8ecff048e50284ecdf33896c6a2dd30f43393b1 100644
--- a/chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc
+++ b/chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc
@@ -87,29 +87,39 @@ std::unique_ptr<DisplayState> BrailleControllerImpl::GetDisplayState() {
   StartConnecting();
   std::unique_ptr<DisplayState> display_state(new DisplayState);
   if (connection_.get() && connection_->Connected()) {
-    size_t size;
-    if (!connection_->GetDisplaySize(&size)) {
+    unsigned int columns, rows;
+    if (!connection_->GetDisplaySize(&columns, &rows)) {
       Disconnect();
-    } else if (size > 0) {  // size == 0 means no display present.
+    } else if (rows * columns > 0) {
+      // rows * columns == 0 means no display present.
       display_state->available = true;
-      display_state->text_cell_count.reset(new int(size));
+      display_state->text_column_count.reset(new int(columns));
+      display_state->text_row_count.reset(new int(rows));
     }
   }
   return display_state;
 }
 
-void BrailleControllerImpl::WriteDots(const std::vector<char>& cells) {
+void BrailleControllerImpl::WriteDots(const std::vector<char>& cells,
+                                      unsigned int oldCols,

[dmazzoni, 2016/10/17 05:13:05]

"old" is a little confusing to me, I know what you mean but it's not really
"old", it's just the rows and columns of the passed-in array. How about
cells_cols, cells_rows for the input arguments?

[ultimatedbz, 2016/10/17 21:49:46]

Done.

+                                      unsigned int oldRows) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (connection_ && connection_->Connected()) {
-    size_t size;
-    if (!connection_->GetDisplaySize(&size)) {
+    // Row count and column count of current display.
+    unsigned int rows, columns;
+    if (!connection_->GetDisplaySize(&columns, &rows)) {
       Disconnect();
     }
-    std::vector<unsigned char> sizedCells(size);
-    std::memcpy(&sizedCells[0], cells.data(), std::min(cells.size(), size));
-    if (size > cells.size())
-      std::fill(sizedCells.begin() + cells.size(), sizedCells.end(), 0);
-    if (!connection_->WriteDots(&sizedCells[0]))
+    std::vector<unsigned char> sized_cells(rows * columns);
+    for (unsigned int i = 0; i < rows; i++) {
+      for (unsigned int j = 0; j < columns; j++) {
+        // If we go out of the bounds of the old display size, pad with 0.
+        sized_cells[i * columns + j] =
+            (i >= oldRows || j >= oldCols) ? 0 : cells[i * oldCols + j];
+      }
+    }
+
+    if (!connection_->WriteDots(sized_cells))
       Disconnect();
   }
 }