perfetto: consolidate all Python libraries into a single folder

This CL consolidates all the Python libraries which have been written
over the past couple of years into a single top level python/ directory.
This makes it a lot easier to reason about this code, ring-fence
things like build targets and also makes dealing with imports a lot
easier.

Change-Id: Ia0d7637c0993dde51af19ce052e18e4773349596
Bug: 180499808
diff --git a/tools/gen_binary_descriptors b/tools/gen_binary_descriptors
index 5388c48..dbbf8c7 100755
--- a/tools/gen_binary_descriptors
+++ b/tools/gen_binary_descriptors
@@ -26,10 +26,10 @@
 
 SOURCE_TARGET = [
     ('protos/perfetto/trace_processor/trace_processor.proto',
-     'src/trace_processor/python/perfetto/trace_processor/trace_processor.descriptor'
+     'python/perfetto/trace_processor/trace_processor.descriptor'
     ),
     ('protos/perfetto/metrics/metrics.proto',
-     'src/trace_processor/python/perfetto/trace_processor/metrics.descriptor'),
+     'python/perfetto/trace_processor/metrics.descriptor'),
 ]
 
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))