Update V8 version to 7.0

TBR=machenbach@chromium.org
NOTRY=true

Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I13105e27794ebbfdfc57ca351959b92bfbbad7c7
Reviewed-on: https://chromium-review.googlesource.com/1143280
Commit-Queue: Michael Hablich <hablich@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54559}

include/v8-version.h

@@ -8,8 +8,8 @@
 // These macros define the version number for the current version.
 // NOTE these macros are used by some of the tool scripts and the build
 // system so their names cannot be changed without changing the scripts.
-#define V8_MAJOR_VERSION 6
-#define V8_MINOR_VERSION 9
+#define V8_MAJOR_VERSION 7
+#define V8_MINOR_VERSION 0
 #define V8_BUILD_NUMBER 0
 #define V8_PATCH_LEVEL 0