Fixed tab mute button of inactive tab is not clickabl

fix brave/brave-browser#22081

Fixed by calculating tab selectable region properly by
GetWidthOfLargestSelectableRegionBrave() as we moved alert button
to left side.

chromium_src/chrome/browser/ui/views/tabs/tab.cc

@@ -3,6 +3,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "chrome/browser/ui/views/tabs/tab.h"
+
 // Set alert indicator's pos to start of the title and
 // move title after the alert indicator.
 // Title right should respect close btn's space
@@ -17,6 +19,27 @@
 #define BRAVE_UI_VIEWS_TABS_TAB_UPDATE_ICON_VISIBILITY \
   showing_close_button_ &= mouse_hovered();
 
+#define GetWidthOfLargestSelectableRegion \
+  GetWidthOfLargestSelectableRegion_ChromiumImpl
 #include "src/chrome/browser/ui/views/tabs/tab.cc"
 #undef BRAVE_UI_VIEWS_TABS_TAB_UPDATE_ICON_VISIBILITY
 #undef BRAVE_UI_VIEWS_TABS_TAB_ALERT_INDICATOR_POSITION
+#undef GetWidthOfLargestSelectableRegion
+
+// Re-defined because we moved alert button to left side in the tab whereas
+// upstream put it on right side. Need to consider this change for calculating
+// largest selectable region.
+int Tab::GetWidthOfLargestSelectableRegion() const {
+  // Assume the entire region except the area that alert indicator/close buttons
+  // occupied is available for click-to-select.
+  // If neither are visible, the entire tab region is available.
+  int selectable_width = width();
+  if (alert_indicator_button_->GetVisible()) {
+    selectable_width -= alert_indicator_button_->width();
+  }
+
+  if (close_button_->GetVisible())
+    selectable_width -= close_button_->width();
+
+  return std::max(0, selectable_width);
+}

chromium_src/chrome/browser/ui/views/tabs/tab.h

@@ -5,9 +5,16 @@
 
 #ifndef BRAVE_CHROMIUM_SRC_CHROME_BROWSER_UI_VIEWS_TABS_TAB_H_
 #define BRAVE_CHROMIUM_SRC_CHROME_BROWSER_UI_VIEWS_TABS_TAB_H_
+
 #define kMinimumContentsWidthForCloseButtons \
   kMinimumContentsWidthForCloseButtons = 55; \
   static constexpr int kMinimumContentsWidthForCloseButtons_UnUsed
+
+#define GetWidthOfLargestSelectableRegion    \
+  GetWidthOfLargestSelectableRegion() const; \
+  int GetWidthOfLargestSelectableRegion_ChromiumImpl
 #include "src/chrome/browser/ui/views/tabs/tab.h"
 #undef kMinimumContentsWidthForCloseButtons
+#undef GetWidthOfLargestSelectableRegion
+
 #endif  // BRAVE_CHROMIUM_SRC_CHROME_BROWSER_UI_VIEWS_TABS_TAB_H_