Reland of V2 of //tools/binary_size rewrite (diffs).

tools/binary_size/README.md

Index: tools/binary_size/README.md
diff --git a/tools/binary_size/README.md b/tools/binary_size/README.md
index e545b33e1c69da055df159ab19e4fb3f14089910..192070c9d3913331f0116e079ac75948a8174688 100644
--- a/tools/binary_size/README.md
+++ b/tools/binary_size/README.md
@@ -1,17 +1,17 @@
-# analyze.py
+# map2size.py
 
-Parses and processes a linker .map file and outputs the result as a .size file.
+Parses a linker .map(.gz) file and outputs the result as a .size(.gz) file.
 
 ## Example Usage:
 
     # Android:
     gn gen out/Release --args='target_os="android" is_official_build=true'
     ninja -C out/Release -j 1000 libchrome.so
-    tools/binary_size/analyze.py out/Release/lib.unstripped/libchrome.so.map.gz --output chrome.size -v
+    tools/binary_size/map2size.py out/Release/lib.unstripped/libchrome.so.map.gz chrome.size -v
     # Linux:
     gn gen out/Release --args='is_official_build=true'
     ninja -C out/Release -j 1000 chrome
-    tools/binary_size/analyze.py out/Release/chrome.map.gz --output chrome.size -v
+    tools/binary_size/map2size.py out/Release/chrome.map.gz chrome.size -v
 
 # create_html_breakdown.py
 
@@ -22,35 +22,37 @@ Creates an interactive size breakdown as a stand-alone html report.
     tools/binary_size/create_html_breakdown.py chrome.size --report-dir size-report -v
     xdg-open size-report/index.html
 
-# query.py
+# console.py
 
 Starts a Python interpreter where you can run custom queries.
 
 ## Example Usage:
 
-    # Run a single query and exit rather than entering interactive mode:
-    tools/binary_size/query.py chrome.size --query 'all_syms.WhereBiggerThan(1000)'
+    # Runs a single diff and exits (does not enter interactive mode).
+    tools/binary_size/console.py without_patch.size with_patch.size --query='Diff(size_info2, size_info1)'
 
-    # Enters a Python REPL:
-    tools/binary_size/query.py chrome.size
+    # Enters a Python REPL (it will print more guidance).
+    tools/binary_size/console.py chrome.size
 
 # Roadmap:
 
   Tracked in https://crbug.com/681694
 
-  1. Convert explain_binary_size_delta.py to use new data model.
-  1. More query.py features:
+  1. Better serialization format (finalize it before people start to use it).
+      * Store only mangled names.
+      * Save space by clustering by path (in addition to section_name).
+  1. More console.py features:
       * Template Symbols - shows when templates lead to code bloat.
       * Duplicate Symbols - shows when statics in headers are an issue.
       * Overloaded Symbols - shows when overloads are excessive.
       * Per-class / namespace size (no way to distinguish class vs namespace).
       * Per-Chrome package (Chrome-specific grouping. e.g. name prefixes).
-      * An interactive UI (either drop into python or use a web server).
+      * CSV output (for pasting into a spreadsheet).
   1. More create_html_breakdown.py features:
       * Convert paths from .o path to .cc path (better breakdowns).
-      * Break down by query.py groupings (use query.py to define GroupBy()s,
-        then render to html graph)
-  1. More analysis.py features:
+        * Via "ninja -t commands libchrome.so" (3 seconds on my machine).
+      * Break down by other groupings (e.g. create from nested `SymbolGroups`)
+  1. More `map2size.py` features:
       * Find out more about 0xffffffffffffffff addresses, and why such large
         gaps exist after them.
       * Use nm to get the full list of symbols that share the same address.