Compile specific parts of the Android build with -O2.

base/allocator/allocator.gyp

Index: base/allocator/allocator.gyp
diff --git a/base/allocator/allocator.gyp b/base/allocator/allocator.gyp
index 323d79ede60e66be555c12d47f2b1c7abc712962..ea960305bac788a143ccacc1bffe8aadba60d0f7 100644
--- a/base/allocator/allocator.gyp
+++ b/base/allocator/allocator.gyp
@@ -12,6 +12,16 @@
       # Run time checks are incompatible with any level of optimizations.
       'win_debug_RuntimeChecks': '0',
     },
+    'configurations': {
+      'Release': {
+        'conditions': [
+          ['OS=="android"', {
+            'cflags!': ['-Os'],
+            'cflags': ['-O2'],
+          }],
+        ],
+      },
+    },
   },
   'variables': {
     'tcmalloc_dir': '../../third_party/tcmalloc/chromium',