Calculate memory thresholds that V8 can use to control GC.
Calculate memory thresholds that V8 can use to control GC.

V8 can be smarter about the memory it uses and the frequency
of garbage collection but we need to inform it of the values
to use. As this varies device to device look it up and store
it on the WebViewCore to be read by native code over JNI.

See also https://android-git.corp.google.com/g/#change,78691

Bug: 3075565

Change-Id: Ib52f4df775b80b386fc98f1d71b5687f01c12b2e

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base