fix: correctly display zoom in accelerator on mac (backport: 4-0-x) (#15626)

* fix: correctly display zoom in accelerator on mac

* add original CL

patches/common/chromium/.patches

@@ -79,3 +79,4 @@ content_browser_main_loop.patch
 dump_syms.patch
 web_preferences.patch
 verbose_generate_breakpad_symbols.patch
+fix_zoom_display.patch

patches/common/chromium/fix_zoom_display.patch

@@ -0,0 +1,31 @@
+From 0000000000000000000000000000000000000000 Web Oct 31 00:00:00 2001
+From: Shelley Vohr <[email protected]>
+Date: Web, 31 Oct 2018 09:08:02 -0700
+Subject: fix_zoom_display.patch
+
+Backport of https://chromium-review.googlesource.com/c/chromium/src/+/1157224. 
+This patch was released in 70.0.3512.0.
+
+diff --git a/ui/base/accelerators/platform_accelerator_cocoa.mm b/ui/base/accelerators/platform_accelerator_cocoa.mm
+index 9786168be893..3c177060453a 100644
+--- a/ui/base/accelerators/platform_accelerator_cocoa.mm
++++ b/ui/base/accelerators/platform_accelerator_cocoa.mm
+@@ -25,9 +25,16 @@ void GetKeyEquivalentAndModifierMaskFromAccelerator(
+   if (accelerator.IsCmdDown())
+     cocoa_modifiers |= NSEventModifierFlagCommand;
+   unichar shifted_character;
++  unichar character;
+   int result = ui::MacKeyCodeForWindowsKeyCode(
+-      accelerator.key_code(), cocoa_modifiers, &shifted_character, nullptr);
+-  DCHECK(result != -1);
++      accelerator.key_code(), cocoa_modifiers, &shifted_character, &character);
++  DCHECK_NE(result, -1);
++
++  // If the key equivalent is itself shifted, then drop Shift from the modifier
++  // flags, otherwise Shift will be required. E.g., curly braces and plus are
++  // both inherently shifted, so the key equivalents shouldn't require Shift.
++  if (shifted_character != character)
++    cocoa_modifiers &= ~NSEventModifierFlagShift;
+   *key_equivalent = [NSString stringWithFormat:@"%C", shifted_character];
+   *modifier_mask = cocoa_modifiers;
+ }