Increment theme browser pack version.

This change is meant for forcing theme property recalculation in M75.

Bug: 942135
Change-Id: Ie6c912234906702381ea5fc5fc5919eb1e14ad99
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1585321Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654673}

chrome/browser/themes/browser_theme_pack.cc

@@ -60,7 +60,7 @@ constexpr int kTallestFrameHeight = kTallestTabHeight + 19;
 // change default theme assets, if you need themes to recreate their generated
 // images (which are cached), or if you changed how missing values are
 // generated.
-const int kThemePackVersion = 64;
+const int kThemePackVersion = 65;
 
 // IDs that are in the DataPack won't clash with the positive integer
 // uint16_t. kHeaderID should always have the maximum value because we want the